Shop slang for low-carbon bolts sold loose or from bulk bins, usually Grade 2 or ungraded, with a bright zinc finish and often no maker's mark. Calling a fastener hardware-store grade means it is fine for shelving and fence gates and not for brakes, suspension, lifting gear or machine guards. The fix is graded, marked fasteners with traceability from an industrial supplier.
Guard was hanging off hardware-store grade bolts, not a mark on the heads, they just stretched and let go.
Also heard as
- no-name bolt
Related terms
Grade 8
Shop shorthand for the strongest common inch bolt, and loosely for anything overbuilt; six lines on the head.
SAE grade
The inch bolt strength system, chiefly Grades 2, 5 and 8, identified by radial lines on the head.
Head marking
The grade symbols and maker's mark stamped on a bolt head, the main clue to its strength once it leaves the box.
Mill cert
Shop name for the material test report tracing steel back to its mill heat, chemistry and test results.