STAINLESS STEEL SELF TAPPING INSERT TYPE 302

Self Tapping Insert Type 302 — A self tapping insert isn't a screw at all — it's a threaded bushing whose external thread self-taps into a pre-drilled pilot hole in thin, soft, or repeatedly-assembled parent material, while the internal thread it presents is a standard machine-screw form, ready to accept an ordinary bolt or screw. The point of using one instead of tapping the host material directly is durability under reassembly: a screw driven straight into soft aluminium, plastic, or thin sheet wears the hole a little more each time it's removed and refitted, and eventually the thread fails; an insert provides a harder, more wear-resistant thread that absorbs that repeated cycling instead, which matters wherever an assembly is expected to be serviced, adjusted, or taken apart more than once or twice over its life — access panels, equipment covers, and jigs or fixtures used in production are typical examples. "Type 302" identifies this specific insert style within PTS's self tapping insert range, distinguishing it by its particular external thread form and driving method from other insert types stocked alongside it; where the precise specification matters, checking the exact product code against the drawing is worth doing rather than assuming all self tapping inserts are equivalent. Grade selection follows the same reasoning as elsewhere in the range: A2 stainless is more than sufficient for general indoor use, while A4 is worth the extra cost where the insert sits in equipment exposed to sustained chloride attack — coastal, marine, or washdown environments — since a corroding insert is far harder to inspect or replace than a corroding screw sitting on the surface. Sizing hinges on getting the pilot hole diameter right for the insert's outer thread, and matching the insert's internal thread size and pitch to whatever machine screw or bolt the assembly is designed around, since a mismatch defeats the entire purpose of fitting an insert in the first place.

FAQs
How is pilot hole diameter determined for this insert?
It needs to match the insert's outer thread form precisely — too loose and the insert won't grip, too tight and it becomes difficult to install or risks damaging the host material.

Is A4 stainless worth specifying for this insert type?
Yes, where the insert sits in equipment exposed to sustained chloride attack, since a corroding insert is far harder to inspect or replace than a corroding surface screw.

What machine screw or bolt sizes does the internal thread typically match?
The internal thread follows a standard machine-thread form, so it should be matched to whatever screw or bolt size the assembly is designed to accept.

How is a self tapping insert different from a rivet nut or threaded bush?
All three provide a durable internal thread in soft or thin material, but a self tapping insert forms its own external thread into a plain pilot hole rather than clamping in place like a rivet nut or requiring a pressed or bonded fit like some threaded bushes.