Toprecision — Precision Fastening & Connection Solutions

Torque tables are the most reused — and most misapplied — documents in fastening. They are calculated, not measured, and that shapes when to trust them.

Bottom line: for most Anti-Loosening Series applications the decision comes down to load, environment and assembly method — the Anti-Loosening Series guide walks through the selection.

The calculation behind the table

Table values derive from T = K·F·d: target preload (typically 75% of proof load) times nominal diameter times a friction factor K, commonly 0.14–0.16 for lubricated steel and 0.18–0.21 dry. Change any input and the "standard" torque is wrong for your joint.

Four conditions that invalidate the table

• Coating: zinc-nickel vs plain zinc shifts K by 0.03–0.05 — a 20% preload swing.
• Lubrication: oil, wax or threadlocker each rewrite the friction budget.
• Parent material: aluminum threads cap preload by strip-out, not bolt strength.
• Repeated assembly: prevailing-torque hardware adds to installation torque; tables rarely account for it.

Build your own table in an afternoon

Test five screws of your actual specification into your actual joint, measure preload (force washer or ultrasonic), derive your K, apply scatter margin. Topprecision supplies K-factor data per coating and helps customers derive joint-specific torque windows — the difference between catalog numbers and working numbers.

Key specifications at a glance

Need fastener engineering support?

Toprecision manufactures precision fasteners in-house — send the drawing, service environment and annual volume. We will recommend the material, grade, coating and process that match the joint requirement. Request a fastener consult.