Stainless Steel T Bolt

Choosing the Right T-Bolt
1) What is a T-bolt & when to use it?

A T-bolt (T-head bolt / channel bolt / hammer bolt) has a T-shaped head designed to fit into a slot, channel, or profile, so the head locks by rotation and provides a threaded stud for clamping.

Use a T-bolt when you need:

Fast, adjustable fixing along a slot or channel

To clamp parts to strut channels, Unistrut, solar rails, or aluminium profiles

To fix items onto machine T-slots, jigs, fixtures, or mounting rails

Typical applications:

Strut/channel support systems (cable trays, ducts, pipes)

Solar panel mounting (rails and clamps)

Aluminium profile systems (Bosch-type)

Machine beds, T-slot tables, jigs & fixtures

T-bolts allow tool access only from the nut side, while the head stays hidden and locked inside the slot.

2) Environment & corrosion – material choice (A2 vs A4)

For stainless T-bolts:

A2 (304) stainless T-bolt

For indoor and general outdoor environments

Electrical supports, machinery frames, plant utility systems, standard roof-top solar (non-marine)

A4 (316) stainless T-bolt

For marine, coastal, chemical, or chloride-rich environments

Coastal solar, treatment plants, chemical plant supports, harsh industrial atmospheres

Match the system:

A2 T-bolt with A2 nuts, washers, and spring channels

A4 T-bolt with A4 nuts, washers, and compatible hardware

3) Channel / slot compatibility – head size & type

The first selection step for a T-bolt is the channel/T-slot system it fits:

Strut/channel systems

T-bolt head dimensions must match the channel opening & lip so that:

Head passes through the slot

Then rotates 90° and bears properly on the lips

Some designs have spring-loaded T-bolts (with a spring under the head) to hold them in place during assembly.

Aluminium profiles / T-slot tables

Head dimensions and shape match specific profile series (e.g., 30×30, 40×40, 45 series) or machine T-slots.

Use the correct T-bolt type/size recommended for that profile/T-slot.

Key point:

Always ensure the T-head dimensions are compatible with the channel/slot you are using – wrong head size can cause tilting, poor bearing, or pull-through.

4) Thread size & length

Select thread diameter based on:

Required clamp load (M6, M8, M10, M12 etc.)

Channel/profile capacity and connected part thickness

Length selection:

Bolt length must cover:

Channel depth + any packing/plates

Thickness of the item being clamped

Washers / spring elements

Nut height + 2–3 visible threads

If you plan to use thick brackets, multiple parts, or two nuts, allow extra length.

Mechanical Properties (Guide) – Stainless Steel T-Bolts

T-bolts follow the same property class system as standard stainless hex bolts.
The T-head shape is for anchoring in a slot; the thread strength is governed by the property class.

A2-70 Stainless T-Bolts

Material: A2 (304) stainless steel

Property class: 70

Minimum tensile strength ≈ 700 MPa

Typical proof strength ≈ 450 MPa

Use with: A2-70 nuts and appropriate washers/channel nuts.

Typical applications:

Strut/channels & supports in buildings and plants

Aluminium profile framing and machine guards

General solar mounting in non-marine environments

A4-70 Stainless T-Bolts

Material: A4 (316) stainless steel

Property class: 70

Same mechanical level as A2-70, with higher corrosion resistance

Use with: A4-70 nuts and A4 washers/channel components.

Typical applications:

Coastal & marine solar structures

Chemical/process plants, water treatment, poolside structures

Stainless/aluminium support systems exposed to chlorides and aggressive cleaners

A4-80 Stainless T-Bolts (if used)

Material: high-strength A4 (316) stainless

Property class: 80

Minimum tensile strength ≈ 800 MPa

Typical proof strength ≈ 600 MPa

Used when:

Higher clamp load is needed in the same diameter, and

Environment requires 316-level corrosion resistance