STAINLESS STEEL SLOT PAN SHOULDER SCREWS DIN 923

Slot Pan Shoulder Screws DIN 923 — Unlike a standard machine screw, a shoulder screw isn't there purely to clamp two faces together — it carries a precision-ground plain shank section, distinct in diameter from the threaded portion, that locates or pivots a component rather than just holding it down. DIN 923 pairs that shoulder with a slotted pan head, so once the shoulder is correctly seated, final tightening is a straightforward hand or screwdriver operation. Typical roles include pivot points for levers, cams and linkages, precision spacers between two components, and location features in jigs, fixtures and machine guides — anywhere a controlled running or sliding fit matters more than raw clamp force.

Because the shoulder — not the thread — carries the functional load, its diameter is deliberately larger than the thread and held to a closer tolerance than a standard clearance-hole fastener, since it often forms a running or location fit against a bushing or bore. DIN 923 defines that shoulder diameter and length alongside the pan head geometry and slot proportions, giving a consistent part for interchangeability across suppliers; the specific tolerance class needed should always be checked against the mating component's fit requirements, since running fits and location fits call for different bands.

Grade selection follows general machine screw logic: A2 stainless is more than adequate for shoulder screws used indoors in jigs, fixtures and general machine guides. A4 becomes worthwhile where the pivot or spacer sits in a washdown, marine or otherwise chloride-exposed environment, since pitting corrosion on a precision-toleranced shoulder can quickly turn a smooth running fit into a seized or sloppy one — a failure mode A2 is more vulnerable to over time in those conditions.

Selecting the right part means matching both the shoulder diameter to the bore or bushing it will run in, and the thread size to the tapped hole securing it — the two dimensions are independent and both need checking against the drawing.

FAQs
How does a shoulder screw differ from a standard pan head machine screw?
A standard machine screw is threaded along most or all of its length and is intended purely as a fastener. A shoulder screw has a defined unthreaded shoulder diameter, distinct from the thread diameter, designed to bear load or provide a running/pivot surface rather than to clamp two threaded faces together.

Does the shoulder diameter match the thread diameter?
No. The shoulder is deliberately a different, usually larger, diameter than the screw thread, and it's the shoulder — not the thread — that carries the functional load in pivot or spacer applications.

What tolerance should I expect on the shoulder?
Shoulder diameters on DIN 923 screws are held to closer tolerances than standard clearance-hole fasteners, since the shoulder often forms a running or location fit. Confirm the specific tolerance class required against your application's fit needs when ordering, as running and location fits can call for different bands depending on the mating component.