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Facts About CPSC's Proposed Table Saw Rule

Revised July 2024

Facts About CPSC’s Proposed Table Saw Rule




Concerns with the CPSC SNPR

Statutory Authority

  • Voluntary standards are working to enhance table saw safety. CPSC is required by law to rely on voluntary safety standards when the voluntary standard adequately addresses the product hazard and is likely to have substantial compliance - which it does.


  • PTI is a voluntary trade organization representing major manufacturers of portable and stationary power tools.
  • There are nine member companies, five of which manufacture table saws. Member companies employ over 13,000 people with facilities in 40 states and employees in all 50 states.
  • Members represent numerous brands of power tools, e.g. Black & Decker, DeWalt, Milwaukee, Ryobi, Ridgid, Bosch, Festool, Dremel, RotoZip, Hitachi, Makita, Skil, Hilti and Metabo.


  • SawStop saws are currently available in the marketplace to any consumer who chooses to purchase them.
  • SawStop introduced a saw for the benchtop table saw market in March of 2015. A SawStop jobsite (professional) saw currently retails between $1,300 - $1,600, while other professional benchtop table saws can be found from $400 - $650. SawStop also recently introduced a smaller (consumer) version weighing 68 pounds starting at $899 compared to other consumer benchtop table saws of similar size, weight and features, (without the injury mitigation system, but including a modular guard system) from $150 – $400.
  • SawStop technology mitigates the hazard of a spinning saw blade when a human hand or finger touches the blade by jamming a braking pawl into the saw blade, thus stopping the blade in milliseconds and destroying the blade.
  • Activation of the SawStop brake results in additional costs to the owner in the form of a new blade ($60-$80) and new brake cartridge ($95-$130). Unintended/false activations and replacement cartridge sales indicates an activation rate of more than one per year, increasing the costs of saw with SawStop technology significantly.
  • The SawStop technology cannot be retrofitted to existing table saws.


  • At one time SawStop approached table saw manufacturers offering to license its patent portfolio technology, demanding an 8% royalty on the retail value of all table saws with the technology in addition to other terms that were onerous and not related to table saw safety.
  • A table saw manufacturer that is not a member of PTI tried to license SawStop’s patent portfolio technology, but negotiations failed when the manufacturer alleged that SawStop demanded unreasonable royalties in excess of what was originally being sought. An additional manufacturer of table saws that also is not a member of PTI reported that the company closed a manufacturing facility in Canada because of SawStop and that efforts to negotiate with SawStop were unsuccessful, noting "They don't want to share...they don't want to share with anybody."
  • If the Commission were to require SawStop technology on table saws, there can be no assurance that SawStop would willingly license technology on reasonable terms. In fact, if the government effectively requires use of the SawStop technology, SawStop could demand any license terms it wants or not grant any license at all. PTI and its members, of course, have nothing against patents. PTI does, however, question whether SawStop should be allowed to use the government to mandate the use of a technology that is so broadly covered with a web of patents and thereby force its competitors to incur exorbitant license fees and/or expensive patent litigation (which costs will be passed on to the consumers).
  • In a court document filed in the U.S. District Court, District of Oregon, Mr. Gass stated "In recent years, we have declined various offers to license our technology."
  • In 2014, UL, in compliance with its Patent Policy, requested that SawStop identify specific patent claims that are essential for compliance with AIM requirements which were being considered for incorporation into the UL 987 standard. In response, SawStop declined to provide any type of statement concerning its patents, other than to say it reserves all its patent rights.

Unresolved Patent Issues

  • Stephen Gass (SawStop), a patent attorney, has approximately 75 active issued U.S. patents which pertain to the SawStop technology, and has several pending patent applications. The SNPR notes some SawStop patents, including the two patents that Bosch was found to infringe (see below), have expired recently but several still have term, including some very broad AIM-related patents with term into the 2030s. Stephen Gass told the CPSC Commissioners that they should assume that no manufacturer will be able to introduce injury mitigation technology that does not infringe his patents.
  • Even with SawStop’s recent announcement to make Pat. No. 9,724,840 available to the public if the CPSC rule moves forward, SawStop has many other patents that could be infringed upon if the rule moves forward. SawStop has no FRAND agreements for its patents and to date, has consistently declined to license any of its other patents.
  • In fact, in May 2024, SawStop filed a patent lawsuit against Felder KG, a manufacturer of woodworking saws whose technology was cited in the CPSC SNPR as an alternative to SawStop's technology.
  • Moreover, some patents with long terms are not limited in their scope to a particular enabling technology for active injury mitigation (AIM). Some patents instead ostensibly cover any AIM that meets a particular performance standard, such as reacting rapidly in response to contact detection.
  • As one example, U.S. Patent 8,061,245 ostensibly covers using the angular momentum of the blade to retract the blade in response to detection of a person contacting the blade. This patent expires in 2026. Any table saw blade with a change in the rate at which the blade spins has an angular momentum that can aid in retracting the blade. Thus, this patent could limit a manufacturer’s ability to make AIM technology with a retracting blade. Furthermore, under U.S. Patent Law, a manufacturer cannot create or test any prototypes incorporating this patent and any other essential patent until after the patents have expired. Accordingly, any substantive research and development can only begin after the essential patents have expired.
  • In 2015 when Bosch introduced its REAXX bench table saw that retracted the blade in response to contact detection, SawStop sought and obtained from the International Trade Commission an order blocking importation of the REAXX saw into the United States due to its infringement of six SawStop’s patents (four have since expired and two remain in force into 2024).
  • In July 2017, TTS Tooltechnic Systems, a company located in Germany, acquired SawStop, LLC and SD3, LLC. According to the United States Patent and Trademark Office patent assignment database, SD3 (SawStop’s parent company) owns the SawStop patents.
  • This sale and change in control of the companies calls into question whatever prior commitments Mr. Gass made to the CPSC regarding licensing the SD3 patents under a mandatory rule. From the SNPR and Briefing Package: However, TTS has also said that “given the breadth of intellectual property that has been developed by SawStop, it no longer is a simple matter to say what such a license would or should include and what structure it would be” (communication between Mr. Fabian Klopfer, CEO of TTS, and Mark Bailey, US CPSC, June 1, 2019).
  • In response to Commissioner Feldman’s questions relating to this rulemaking, SawStop Holding, LLC (formerly known as SD3, LLC, and the owner of SawStop, LLC) and SawStop, LLC stated that they “do not know” whether any of their intellectual property or patents are essential to the Commission’s proposed rule in the SNPR. They also did not commit to licensing the patent; instead they stated that they are “evaluating whether to commit either to making that patent freely available to competitors for use in the United States or to licensing that patent on FRAND terms if the Commission enacts as a rule the safety standard presented in the current SNPR.”
  • In other words, if the patent web of SawStop cannot be avoided, the Commission would in effect be imposing a design standard, rather than a performance standard. The mandatory rule would create a monopolistic advantage in the marketplace, generating millions of dollars for SawStop, and raising costs for consumers.

Unintended Consequences Of The SawStop Technology

  • Data supplied by SawStop concerning the number of table saw units sold and the number of reported blade contact incidences, demonstrates that operators are nearly five times more likely to contact the saw blade of a SawStop saw as opposed to the operator of a conventional table saw.
  • Logic dictates that this increase in accident rate on SawStop saws is due primarily to a user’s decision to use the blade guard less frequently or not at all due to a “sense of security” in having the SawStop flesh-sensing technology on the saw.
  • The reduced rate of using the blade guarding system will result in increased rate of facial or eye injuries caused by high velocity particles ejected by the saw blade or injuries caused by workpiece kickback.
  • The increased cost of even the least expensive table saws, as discussed in this document, may result in power tool users resorting to unsafe methods (for example: using portable hand held circular saw in inverted position) to accomplish cuts normally performed on a table saw.
  • The rising population in the 1980's of the affordable and safe benchtop saw resulted in a decrease in accidents from circular saws being used improperly. If benchtop saws become drastically more expensive or manufacturers withdraw from the market, there is likely to be a return to improper use of circular saws and unintended declines in safety.

Alternative Technology

  • PTI Joint Venture has developed a flesh sensing technology that reacts faster, has a lower replacement cost of firing, and mitigates injury to a greater degree when compared to the SawStop technology. In light of the patent situation, manufacturers must consider that introducing this alternative technology will result in costly patent infringement litigation (estimated to be at least 7-10 million dollars for each party) with uncertain outcomes. This scenario has come to fruition by the patent infringement action filed by SawStop against the Bosch REAXX™ saw.
  • The SNPR notes that new Preventative Contact System (PCS) proximity sensing technology by Felder has been introduced on a commercial sliding table panel saw. Commercial saws are outside of scope of CPSC’s jurisdiction, and there has been no demonstration that PCS technology, is viable on benchtop table saws. The only model (KAPPA 550) sold at this time is priced at over 44,620 Euros and not available in the U.S. In addition, no analysis of potential patent requirements has been conducted by the CPSC on this technology. And in May 2024, as noted above, SawStop filed a patent lawsuit against Felder KG.
  • The other alternative technology cited by CPSC is the Altendorf Hand Guard safety system, optical sensor technology which utilizes two overhead optical cameras independent of the mechanical saw blade barrier guards to monitor and recognize dangerous hand to saw blade positions. This overhead camera position system is not suitable for small transportable benchtop table saws, and the additional cost of the technology is reported to be over $15,000.

Injuries and Data

SawStop Active Injury Mitigation System

  • SawStop cannot mitigate fractures and crushing injuries caused by workpiece kickback or loss of vision caused by high velocity particles ejected by the saw blade.
  • SawStop technology can mitigate only injuries caused by a contact with the blade, therefore, only blade contact injuries should be considered as part of the rulemaking in light of the petition.
  • The SawStop technology does not prevent an injury, it can only mitigate the outcome of the injury based on the approach velocity of the human flesh. As such, significant injuries are still possible.

Incident Data

  • The estimated population of all table saws on the market in the US for 2001/2002 was 8.0 million and for 2007/2008 was 9.5 million. CPSC did not provide updated numbers of saws in use within the SNPR, and thus appears to be relying on data over 15 years old.
  • Within the SNPR, the blade contact injury rate estimates by CPSC for all table saw categories combined, for 2010-2021 are fluctuating, but for the 2002-2006 the average NEISS reported injuries were 37,243, for the 2007-2015 were 34,040 and for the 2016-2021 were 33,791. Comparing 2002-2006 (traditional blade guard (TBG) years) to 2016-2021 (modular blade guard (MBG) years) there is a 9.3% decrease, attributable to the MBG penetration on the table saws in use. And these reductions in risk from adoption of MBG technology are occurring even though full penetration of MBG protection into the marketplace on all table saw types will not be achieved for many years.
  • In the benchtop category, table saws have an average life of 7.5 years but some remain in use for more than 15 years, so 100% market penetration of risk-reducing MBG technology won’t occur until at least 2026. For the contractor category of table saws, the average life span is 17 years with some saws lasting more than 30 years, meaning 100% compliance with MBG won’t occur until at least 2041. Cabinet table saws have an average lifespan of 24 years, but many remain in active use for up to 50 years, so 100% MBG compliance may not be achieved until 2060 or later.
  • CPSC in 2011 published Survey of Injuries Involving Table Saws for the 2007- 2008 years addressing the distribution of accidents per table saw categories, concluding that benchtop table saws account for 10.5%, contractor saws for 18.3%, and cabinet saws for 68.7% of injuries. There is inconsistency of CPSC’s injury contribution reports by table saw category range in the SNPR to a complete reversal of 60.9% for benchtop, 27.1% for contractor and 9.1% for cabinet table saws, and anything between the two extremes.
  • The CPSC SNPR claims there are a total of 49,176 medically treated blade contact injuries for all table saw categories, approximately 29,948 (60.9%) of which they attribute to benchtop saws. In contrast, PTI members, who make up more than half of all benchtop saw on the market, have reported 25 blade contact injuries involving benchtop table saw over a six-year period, that overlaps 2017, a year when both MBG and TBG were in use.
  • If the PTI documented injury rate is applied to the entire benchtop table saw population of 5.35 million saws in use during 2017, there would be only 74 documented benchtop table saw injuries.
  • In 2014, following an inquiry from plaintiff's counsel, CPSC staff developed documents attempting to redistribute the proportion of injuries for various table saw categories. PTI objects to CPSC staff's attempt to use a confusing questionnaire of responses to the "drive type" survey question as the basis for injury estimates re-classification of the type of table saws.
  • CPSC’s attempt to use the “drive type” as the basis for distribution of table saw categories is flawed since the defined terms of “direct” and “indirect” drives for table saw is technically incorrect. Actually, there is no UL/ANSI approved table saw in the US that could be classified as “direct drive” according to the CPSC definition of that term. Every UL/ANSI approved table saw, (bench, contractor, or cabinet style) would be classified as “indirect drive” according to the CPSC definition of that term.
  • PTI, through a FOIA request, obtained the actual In Depth Investigation (IDI) reports that the CPSC staff was trying to use for justification of claims that the majority of injuries are associated with the benchtop category of table saws. The CPSC spread sheet titled “IDIs-NEISS special study (CPaul product type analysis)” that was used to resolve the contradiction between the term of “table saw category” (Q99) and the “drive type” (Q145) despite still having numerous flows, actually shows that majority of injuries (54.3%) are associated with the “cabinet style” table saws.
  • CPSC has since concluded that results from the 2007-2008 special study, along with a second special study conducted in 2014-15 should be discounted, leaving CPSC without the necessary data to substantiate the proposed rule and eliminating the original substantiation on which the proposed rule was based.

Modular Blade Guard

  • From 2007 through 2021, PTI members introduced over 7 million saws (overwhelmingly benchtop and few contractor type table saws) in the U.S. with newly designed modular guarding systems, including a riving knife, which meet the contemporaneous requirements of the applicable editions of the UL 987 standard and the UL 62841-3-1 safety standard. User acceptance of the new modular guarding system has only continued to increase over time since the rulemaking activities in 2017, similar to increasing acceptance of safety technology on other products.
  • CPSC’s 2017 NEISS Table Saw Special Study analyzing accident rates of modular blade guard system equipped table saws compared to table saws equipped with the traditional 3 in 1 blade guarding system, concluded the MBG table saws are seven times less likely to be associated with injuries.
  • A Table Saw Blade Guard Survey completed by CPSC in 2017 to determine modular guard system usage and preferences concluded 71% of users preferred using the modular blade guard compared to the traditional blade guard or no guard at all. 83% report that the modular blade guard prevents hazards associated with operating a table saw to from moderate to large extent.
  • PTI has conducted surveys of the injury rates of table saws with the modular blade guard systems. The first time period covered 2007 through 2015 and included analysis of 92 reported accidents, the second time period from 2016 through 2021 involved analysis of 101 reported accidents. The traditional blade guard injury rate was established based on analysis of 485 reported accidents from 1994 through 2002-time frame. Comparing the injury rates, the modular blade guards showed a demonstrative reduction (3.5 to 1 improvements) in the likelihood of operator blade contact injuries compared to traditional spreader mounted guarding systems.

Societal Cost Of Blade Contact Table Saw Injuries

  • CPSC’s most recent estimate of annual cost of all table saw injuries was $3.91 billion per year, however this estimate ignores the reduction in injuries that are occurring due to the introduction of MBG technology under the current voluntary standard. Along with other errors in the CPSC analysis, an expert 3rd party review of the CPSC’s analysis has found that the annual cost of injuries is at least 50% less than CPSC’s estimates, and is falling over time. The expert review has also found that CPSC underestimates the costs to comply with their proposed rule and the impact of higher table saw prices on consumers by between 60% and 80%. Overall, the 3rd party review has found that CPSCs proposed rule would result in negative net benefits to society of -$388.3 million per year.
  • Making the SawStop technology mandatory for inexpensive and safe bench top table saws is not economically justifiable and it will economically damage consumers who need an inexpensive tool for occasional do-it-yourself (DIY) projects and small self-employed contractors who may not be able to afford the substantial price increase in the bench top category of table saws. In addition to this economic damage to consumers and self-employed contractors, at least some of these categories of table saw consumers will likely opt for less expensive non-table saw products (such as circular or band saws) to perform cutting operations for which a table saw performs more safely and efficiently.

Economic Justification Of New Technologies

  • Economic justification for new technology is an integral part of evaluating feasibility of any alternative technology. Previously, evaluating the costs of Active Injury Mitigation (AIM) for the benchtop category of table saws had been based on estimates, in the absence of an actual market ready product. The March 2015 introduction of the SawStop benchtop table saw at $1,299 and then Bosch announced price point of $1,499 for their bench top table saw significantly changed the situation.
  • In June of 2013, Stephen Gass claimed that an active injury mitigation system could be implemented in any consumer table saw for an increase on the order of $55 to the bill of material cost. He attributed this cost increase to the following components: $20 for brake cartridge, $10 for modified arbor with electrodes, $20 for modified switch box and $5 for cables. However, comparing the actual SawStop table saw construction to the list of components Mr. Gass has listed for the new technology, it is clear that his claimed price estimate does not include many new components that are actually part of the SawStop table saw or components that were redesigned and strengthened at higher cost. Thus the economic feasibility of the AIM technology for benchtop table saws cannot be judged by Mr. Gass' unsubstantiated cost estimates, but it has to be driven by the actual hard cost figures. If AIM could be added to the benchtop category of table saws for the price noted by Dr. Gass, why has he not done it?
  • Portable benchtop table saws currently on the market range in price from $140 to $600. The volume based median price of an existing benchtop table saw is approximately $250.
  • A government regulation mandating a flesh detection technology for all table saws will increase the cost of benchtop table saws that could accommodate the technology by $900-$1,000. Such burden is not justifiable for DIY or small contractor customers.
  • According to the SNPR, in general, the retail prices of bench saws could increase by as much as $285 to $700 per unit, and the retail prices of contractor and cabinet saws could rise by as much as $450 to $1,000 per unit.
  • Activation of the SawStop brake results in additional costs to the owner in the form of a new blade ($60-$80) and new brake cartridge ($95-$130). The available data from SawStop also shows that this additional cartridge/blade cost is likely to be experienced more frequently due to unintended/false activations caused by the blade contacting moist pressure treated wood, static electric discharge, voltage spikes from switch activations, etc.
  • Benchtop table saws priced substantially higher due to the CPSC mandate and additional maintenance costs cannot fulfill consumer expectations for inexpensive reasonably safe lightweight transportable table saws. Even without the CPSC mandate, benchtop saws with AIM technology are already available on the market for buyers who are willing to pay the price for such additional technology. But, with such a dramatic cost increase, it is reasonable to conclude that the high cost of AIM will make this technology economically unreachable for most DIY customers or others who will likely seek less costly and more dangerous alternatives.
  • If the proposed rule is adopted by the Commission, it could be tantamount to the elimination from the market of portable benchtop table saws as we know them today. However, the SNPR does not address any analysis of whether this proposed rule meets the legal requirements for a product ban.

Voluntary Standards Activity

  • CPSC, SawStop, PTI and many other interested parties participate in the Standards Technical Panel (STP) 745 for Electric Tools, under ANSI guidelines that ensure openness, balance, consensus and due process.
  • Hundreds of electric tools are covered under UL/ANSI voluntary standards. There are no electric power tools within the scope of STP 745 that have a mandatory standard.
  • The Commission must rely upon voluntary consumer product standards, rather than adopt a mandatory standard, whenever compliance with such voluntary standards would eliminate or adequately reduce the risk of injury addressed and it is likely that there will be substantial compliance with such voluntary standards.
  • An international safety standard for table saws, IEC 62841-3-1, was published June, 2014. This standard was developed by experts in 22 countries (including the United States) and will result in improved safety requirements for table saws worldwide. The International Body of Experts evaluated whether injury mitigation technology should be included in the IEC standard but determined it should not be included as a mandatory requirement.
  • IEC 62841-3-1 was adopted in the United States and Canada as an ANSI standard and published on August 29, 2016, and continues with routine standard revisions. All table saws sold to consumers in the U.S. meet the requirements of the standard.
  • ANSI, UL, and IEC have a patent policy that states that if a proposed standard may require the use of an essential patent, the patent holder must agree to license under fair and non-discriminatory terms. The CPSC does not have such a policy. As noted above, SawStop has previously refused to comply with this policy.
  • Only 66 of the 437 (15%) 2017 NPR public comments supported developing mandatory regulatory standards for table saws. The other commenters generally opposed the rulemaking proceeding.

Regulatory And Legislative Initiatives

  • In 2012, California introduced legislation that would have required all new table saws sold in the state to be equipped with injury mitigation technology. There was concern that it was a one company bill and it was not taken up by the Senate.
  • In February 2014, SawStop, LLC and SD3 filed an antitrust case in US District Court, Eastern District of Virginia against several manufacturers of table saws, naming the Power Tool Institute and UL as co-conspirators. In October 2016, the Defendants won summary judgment.


  • If the Commission were to adopt a mandatory standard of the type requested in the SawStop Petition, because of the SawStop patent issues, the Commission effectively will be mandating a design requirement, which is not within the Commission's statutory authority.
  • Voluntary standards are working to enhance table saw safety.
  • The cost to consumers and manufacturers of a mandatory standard would far outweigh any benefits that may be realized, particularly if such requirement is applied to the benchtop category of table saws.
  • The Injury Cost Model, economic justification, accident data and other data utilized by the Commission to justify moving forward with the SNPR are flawed and don’t support mandatory CPSC action.
  • AIM technology has been carefully evaluated and debated since its introduction in 2000. Independent research, numerous studies, safety and economic experts and consumers have all reviewed and evaluated the technology. The State of California, UL, IEC and CPSC have all considered whether there should be a mandatory requirement for AIM technology. To date, no regulatory or legislative action has determined table saws require this technology to make them safe and no mandatory requirements have been determined to be necessary.
  • These evaluations, along with the lawsuit against the US PTO, the antitrust suit and the patent infringement cases, suggest the complexities involved in this issue should not be resolved by a mandatory CPSC action. We urge CPSC to consider whether a significant cost increase to consumers, a possible withdrawal of manufacturers from the market, and a possible monopolistic position of one manufacturer are supportive of a mandatory requirement by the government and in the best interest of the consumer.


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