About WhatSizeBolt
WhatSizeBolt answers one question as directly as possible: what size is that fastener? Wrench size, thread pitch, torque spec and OEM part number, for a specific year, make and model, without a forum thread or a paywall in the way.
What we cover
The database holds more than 301,000 individual fastener records across over 17,000 vehicles, alongside small-engine and outdoor power equipment. Coverage is deepest on the jobs people actually look up in a driveway or a shop bay: lug nuts, drain plugs, caliper brackets, head bolts and the fasteners that are easy to strip and expensive to get wrong. Every vehicle page is pre-rendered as real HTML rather than assembled in your browser, so the answer is on the page the moment it loads.
How the data is verified
Fastener data is easy to publish and hard to publish honestly. A torque figure copied from one site to the next acquires authority it never earned, so we track proof at the level of the individual field rather than the page. Each claim about a torque value, wrench size, thread or part number is stored as its own append-only record carrying the source it came from, the application it was observed on, and who reviewed it. Verified means a reviewer certified the value against a named source for a matching application. Unverified means a value is published but has not cleared that review. Conflicting means two credible sources disagree, and the conflict outranks a matching value until someone resolves it with newer source-backed evidence. Stale means the underlying record changed after the evidence was captured, so the old certification no longer counts. A disagreement cannot be buried by editing a number, and a value cannot quietly inherit proof that belonged to a different vehicle.
What we do not claim
This site is a reference, not a substitute for the factory service manual for your specific vehicle. Manufacturers revise specifications mid-model-year, trims differ, and some fasteners are single-use by design and must be replaced rather than re-torqued. Where a spec is critical or safety-related, confirm it against the FSM before you turn a wrench. If you find something wrong, tell us and we will correct it with a sourced record rather than a quiet edit.
How the site is funded
WhatSizeBolt is free to use and is supported by display advertising and by affiliate commissions on tools and parts. When a link earns a commission we say so on the page. Commissions never determine which specification is published or which part is listed as correct. The fastener data and the advertising are kept independent of each other. Corrections, questions and press enquiries go to contact@whatsizebolt.com; please include the year, make and model and the source you are working from.
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