Stainless Steel Dom Bolt

Choosing the Right Dom Bolt (Dome / Button Head Bolt)
1) What is a dom bolt & when to use it?

A dom bolt (dome-head / button-head bolt) is a bolt with a rounded, smooth head instead of a sharp hex profile.

Use a dom bolt when you want:

A clean, finished appearance (visible joints, furniture, covers, panels)

A smooth, low-profile head for safety (no sharp corners to catch clothes/skin)

A more tamper-resistant look (harder to grip with spanners from outside vs hex head)

To match with dom nuts / dome nuts on the other side for a fully rounded, aesthetic assembly

Typical applications:

Architectural & interior hardware – handrails, glass/SS brackets, furniture, enclosures

Machine guards & covers – where people may brush past fasteners

Public areas – playground equipment, benches, kiosks, signage

Decorative stainless structures – façades, railings, SS fabrications

2) Environment & corrosion – A2 vs A4 stainless

Like other stainless bolts, choose A2 vs A4 based on exposure:

A2 (304) dom bolt

For indoor and general outdoor conditions

Office/interior hardware, general structural/architectural work, non-marine outdoor fittings

A4 (316) dom bolt

For marine, coastal, poolside, or chemical environments

Seafront railings, pool ladders, jetties, wash-down and process plant areas

Match the full assembly:

A2 dom bolt + A2 nuts & washers (and A2 dome nuts if used)

A4 dom bolt + A4 nuts & washers (and A4 dome nuts if used)

This keeps the whole joint at the same corrosion level and avoids galvanic issues.

3) Head style & drive type

Dom bolts can be supplied with different head/drive options:

Plain dome / button head with internal hex (Allen)

Rounded, low profile

Tightened with an Allen key from the front

Very clean look, common in architectural & machine covers

Dome head with Torx / tamper-resistant drive

Uses Torx, pin-Torx, or special drives

Adds security where you don’t want casual removal with standard tools

Dome head with external tool faces (less common)

May have special wrench flats under the head or on shank

Used where you still need spanner grip but want a rounded external look

Selection tip:

Visible front face, aesthetics important → dome/button head with internal hex or Torx.

Need some tamper resistance → dom bolt with pin-Torx / security drive.

4) Shank & thread – sizing and length

Dom bolts behave like normal bolts for diameter and thread:

Typical diameters: M4, M5, M6, M8, M10, M12

Standard metric coarse threads (M6×1, M8×1.25, M10×1.5, etc.) unless otherwise specified

Length selection:

Total length must cover:

Material thickness (1 or more plates/parts)

Washer + nut (or dome nut) on the other side

2–3 threads showing beyond the nut (unless you want it perfectly flush and choose length carefully)

When used with dom nuts, some customers prefer just 1–2 threads inside the dome so the nut appears fully filled and neat.

5) Application type – clamping, covers & safety

Dom bolts are ideal where:

Head will be visible and architecture/finish is important

People may touch or bump into fasteners (no sharp hex corners)

You want consistent SS look with polished or brushed finish

You’re combining with dom nuts to create rounded fasteners on both sides of a joint

For pure structural / hidden joints, hex bolts may be more economical; dom bolts are chosen for look + safety rather than extra strength.

Mechanical Properties (Guide) – Stainless Dom Bolts

Dom bolts follow the same property classes as standard stainless bolts.
The dome head gives a different appearance and contact surface, but tensile strength is governed by the material grade + property class.

A2-70 Dom Bolts

Material: A2 (304) stainless steel

Property class: 70

Minimum tensile strength ≈ 700 MPa

Typical proof strength ≈ 450 MPa

Use with: A2-70 nuts / dom nuts and A2 washers

Typical applications:

Interior & exterior architectural SS work

Machine covers, guards, and panels

Furniture, railings, display systems in non-marine environments

A4-70 Dom Bolts

Material: A4 (316) stainless steel

Property class: 70

Same mechanical strength range as A2-70, but higher pitting & corrosion resistance

Use with: A4-70 nuts / dom nuts and A4 washers

Typical applications:

Marine & coastal railings and hardware

Poolside equipment, jetties, docks, ladders

Food & chemical plant areas with wash-down and chlorides

A4-80 Dom Bolts (if used)

Material: high-strength A4 (316) stainless

Property class: 80

Minimum tensile strength ≈ 800 MPa

Typical proof strength ≈ 600 MPa

Use with:

High-strength A4 nuts/dom nuts where higher clamp load is needed in a corrosive environment