T-head bolts to DIN 186, 188, 261 and to drawing

Instead of a hexagon, the T-head bolt has a flat, rectangular head set crosswise to the shank like the head of a hammer. It is pushed through an opening or a T-slot and turned through 90 degrees; it then engages behind the component and pulls against it when the nut is tightened. This creates a joint at points that cannot be reached from the rear. T-head bolts are standardised as DIN 186 with a square neck under the head to prevent rotation, DIN 188 with two nibs, DIN 261 without an anti-rotation feature and DIN 7992 with a large head for steel construction; T-slot bolts to DIN 787 are the small version for machine tool tables.

Where T-head bolts are used

Crane rails and rail fastenings, steel construction and scaffolding, switchgear and transformers, pipe clamps and pipe and cable routes, presses and clamping fixtures, railways and overhead lines. In many plants, they are part of the spare parts stock in special lengths that no stockist carries.

How RS Randack manufactures them

The T-head is hot-forged in a closed die; dies and punches are made in our own toolroom, including for heads to drawing with nibs, square neck, head bore or special dimensions. The grain flow follows the shape of the head, which gives the transition to the shank a high load-bearing capacity. Rolled threads, property classes 4.6 to 10.9, also in stainless steel, surface finishes from bright oiled and blackened to hot-dip galvanised or zinc flake. One-offs to small series in special sizes are typical; marking and certificate as required.

What you should specify

Standard or drawing, head dimensions and anti-rotation feature, diameter and length, thread length, property class or material, nut and washer as an assembly, surface finish, quantity.