Stainless Steel Socket Button Head Screw

Choosing the Right SS Socket Button Head Screw (Guide)
for stainless steel hex socket button head screws – e.g. ISO 7380 / DIN 7380

1. Understand What a Socket Button Head Screw Is

An SS socket button head screw is:

A low, rounded (button) head

With an internal hex socket (Allen) drive

Fully or partially threaded machine screw/bolt

Used with a nut or in a tapped hole

It’s chosen when you want:

A smooth, rounded, low-profile head (no sharp edges)

Allen key tightening (clean look, no external hex)

Medium strength & good aesthetics – panels, guards, covers, machines.

2. Application & Joint Type
a) Where is it used?

Pick a socket button head when:

You have machine covers, guards, panels, housings

You want a neat, smooth, modern look (visible fasteners)

Space is limited for spanner/hex bolt, but Allen key access is easy

There is low to medium load (not extreme structural loading)

Typical uses:

Machinery and equipment covers

Automotive & bike accessories, fabrication, furniture

Electrical and electronic enclosures

Instrument panels, decorative brackets and frames

Not ideal for:

Very high clamp-load or highly stressed structural joints → use hex head or socket cap instead.

3. Environment & Stainless Steel Grade
a) Choose by environment

Normal indoor / general outdoor / mild industrial
→ A2 (SS 304), class A2-70

Standard, economical, good corrosion resistance

Coastal / marine / chemical / high chloride
→ A4 (SS 316), class A4-70 or A4-80

Much better resistance to pitting, crevice corrosion, and chlorides

Cost-sensitive, non-critical, mild atmosphere
→ SS 202 possible (if customer accepts), but:

Lower corrosion resistance

Avoid for long-term outdoor, marine, or chemical use

b) Match surrounding materials

Match grade with other visible fittings (brackets, rails, hinges).

A4 with A4 hardware in marine/chemical areas.

Mechanical Properties (Guide) – SS Socket Button Head Screws

Typically supplied in austenitic stainless steel with strength classes similar to other stainless hex and socket screws:

A2-70 (approx. SS 304)

Material: A2 (≈ SS 304)

Strength class: 70

Minimum tensile strength: ~700 MPa

Proof (yield) strength: ~450 MPa

Typical use:

General machinery

Decorative/visible joints

Indoor & mild outdoor environments

A4-70 (approx. SS 316)

Material: A4 (≈ SS 316)

Strength class: 70

Minimum tensile strength: ~700 MPa

Proof strength: ~450 MPa

Key advantage:

Superior resistance to chlorides, seawater, many chemicals

Typical use:

Marine/coastal fittings

Food & pharma machinery

Chemical plant covers and brackets

A4-80 (higher strength, SS 316)

Material: A4 (SS 316)

Strength class: 80

Minimum tensile strength: ~800 MPa

Proof strength: ~600 MPa

Use when:

Higher clamp load is required

Corrosive environment + more demanding mechanical loads

In practice, for socket button heads, remember:

Geometry (small head + shallow socket) often limits practical torque before socket damage, even if material strength is high.