Vident Partners provides vetted power tool expert witnesses for cases involving table saw and miter saw injuries, nail gun trigger design, kickback, missing or defeated guards, battery fires, and manufacturer and employer liability on job sites and in homes nationwide. Request a referral today.
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A power tool expert answers why this tool hurt this person: was it a design that left a foreseeable hazard, a guard someone removed, or a task the tool was not meant for? Tools are simple machines used at close range, so the hazard is usually known. The fight is over who should have dealt with it, and how. This page covers handheld and benchtop power tools. Fixed plant equipment has the machine guarding page, and a broken part's fracture belongs to a failure analyst.
No tool has drawn more litigation than the table saw, and the record is unusually public. In a 2023 supplemental proposal, the Consumer Product Safety Commission reported an estimated 26,501 blade-contact injuries initially treated in hospital emergency departments in 2017 1. By diagnosis, it estimated about 16,100 lacerations, 5,500 fractures and 2,800 amputations 1. It proposed a performance requirement limiting depth of cut to no more than 3.5 millimeters when a test probe approaches the spinning blade at 1 meter per second, a standard that active injury mitigation technology could meet 1.
That proposal did not become law. In an August 20, 2025 release, CPSC announced it would withdraw several pending rulemakings, and named the table saw standard among them 2. So no mandatory federal performance standard of that kind is in force on that record, and counsel should confirm any later action. Withdrawal does not end a product liability claim. The evidence for a safer alternative design remains in the agency's record, and whether the design is defective is a question of state law.
Nail gun claims often turn on one component. NIOSH and OSHA report that nail guns are responsible for an estimated 37,000 emergency room visits each year, and that the risk of injury is twice as high with a multi-shot contact trigger as with a single-shot sequential trigger 3. Their guidance puts use of the full sequential trigger first among its six steps, along with training, work procedures, protective equipment, encouraging reports, and first aid 3. So one question is which trigger the tool shipped with, and whether a safer one was available at the time of sale. On the job site, the question becomes which the employer chose.
For employers, OSHA's rules are direct:
A removed or wedged guard is the most common fact in these cases. The expert asks who altered it, whether it hampered the work, and whether that was foreseeable. A guard that makes the job hard to do invites defeat, and that is a design question as well as a conduct question.
The analysis starts with the tool itself. The expert preserves it, documents wear and modification, compares it with an exemplar, and tries to reproduce the event safely. Kickback analysis looks at blade condition, feed direction, the riving knife and how the stock was supported. For a battery fire, the expert examines the cell, charger and any aftermarket parts. Labels and manuals matter, and human factors may address whether warnings were understood. The expert should also ask how many similar incidents the maker knew of.
A consumer injury and a job site injury may look alike but differ legally. On a site, workers' compensation usually limits a claim against the employer, so a product claim against the manufacturer becomes the main path.
No license applies. Look for a mechanical engineer with tool design or testing experience, or a safety engineer with field practice. A former tool designer knows what was feasible at the date of sale. A human factors expert addresses use and warnings. A failure analyst addresses a broken part, and a hand surgeon or life care planner addresses the injury and its costs.
NIOSH and OSHA report that nail guns account for an estimated 37,000 emergency room visits each year, and that injury risk is twice as high with a multi-shot contact trigger as with a single-shot sequential trigger.
Case Types
Table saw blade-contact injuries and alternative design claims
Nail gun injuries and contact trigger design
Kickback injuries from saws and grinders
Missing, wedged, or altered guards
Abrasive wheel and grinder failures
Lithium battery and charger fires
Employer failure to supply guarded tools or training
Inadequate warnings and instructions
Qualifications
Related Specialties
FAQ
Look for a mechanical engineer with tool design or testing experience in the same category, or a safety engineer with field practice. The expert should be able to inspect the tool, compare it with an exemplar, and say what designs were feasible at the date of sale.
CPSC proposed one in 2023, limiting depth of cut to 3.5 millimeters under a test. In August 2025 it announced it would withdraw several pending rulemakings, including that one. Counsel should confirm any later action. The record may still matter in a state product liability claim.
NIOSH and OSHA report that injury risk is twice as high with a multi-shot contact trigger as with a single-shot sequential trigger. Their guidance puts use of the full sequential trigger first among six steps. So an expert asks which trigger the tool had and whether a safer one was available.
Under 29 CFR 1910.243, portable, power-driven circular saws with a blade diameter greater than 2 inches must have guards above and below the base plate or shoe. In construction, tools designed to accommodate guards must have them when in use.
That depends on state law and the facts. An expert addresses whether removal was foreseeable, whether the guard hampered the work, and whether a better design would have prevented it. Counsel addresses how the law treats later modification.
In general, power tool expert fees are determined by the expert themselves, based on a variety of criteria. Among those criteria are engineering experience, forensic experience, testing needs, category knowledge, and publications. Vident does have some influence over expert fees by comparing experts within a specialty, but ultimately it is a personal decision by the expert.
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