Clutch-brake lining wear

How it is calculated

Measure the lining thickness with a caliper at three points around the circumference and take the smallest value - linings wear unevenly, and the brake fails at the thinnest spot. Take measurements only with the press stopped and isolated.

Months remaining = (current thickness - minimum from the press passport) / wear per month. Remaining life, % = (current - minimum) / (new - minimum) × 100.

Example with illustrative numbers: new lining 10 mm, minimum 6 mm, now 7.5 mm, wear 0.5 mm per month. Remaining - 3 months, life - 37.5%. Establish monthly wear from two measurements taken one to two months apart under normal press load.

How to read the lining size

Lining dimensions are usually written as four numbers, for example 260×220×4×60:

Why you must not run below the minimum

• A thin lining means a larger gap and extended springs that clamp with less force, so the brake cannot stop the ram at top dead centre in time. The ram overruns - a direct risk of hand injury in the die.
• Below the minimum thickness the mounting metal starts rubbing on the disc, and you end up replacing more than the linings.
• A growing ram overrun angle is the first sign the linings are at the limit. Check it against the press passport.
• Order linings in advance, when remaining life drops to about a third, so the replacement is planned rather than an emergency.
• Replace linings as a full set for the clutch or brake, not one at a time.

Where to find linings

Find sizes for your machine in press spare parts by model and ready items in brake linings. If there is no passport, send the dimensions of the old lining or a drawing.