FF-S-210 — Setscrews: Square Head & Slotted Headless

FF-S-210 covers two related but distinct setscrew configurations: square head setscrews (inch series only), which have a protruding square head that can be driven with a wrench, and slotted headless setscrews (available in both inch and metric series), driven with a standard flat-blade screwdriver rather than a socket.

Square head setscrews are typically used where the fastener is not fully recessed and external wrenching access is available or preferred — for example, in older machinery or where a socket-drive tool isn't practical. Slotted headless setscrews serve the same locating function as FF-S-200's socket-drive versions but use a slot rather than an internal hex or spline recess, which can be advantageous where a standard screwdriver is more readily available than a hex key.

• FF-S-210 and FF-S-200 jointly replaced the earlier consolidated setscrew specification, FF-S-103, when that document was cancelled.
• The most recent notice, Notice 1 (15 December 2000), confirms the document remains valid for use even though it's not actively revised for new configurations.