Mandrel bars

Mandrel bars

GMH Gruppe is a leading supplier of high-grade mandrel bars. Our mandrel bars form hot-rolled, seamless tubes and pipes, components indispensible in sectors such as energy and automotive.

Request Quotation


Mandrel bars are used as piercing tools in the production of seamless hot-rolled tubes and pipes. Pre-pierced steel billets are rolled to hollows by means of mandrel bars. From these hollows, tubes and pipes are produced using a range of forming and finish-rolling processes. During the piercing process, the mandrel bars are subjected to extreme stresses, and the material properties and dimensions of our mandrel bars are therefore precisely adjusted to their specific conditions of use.

Production process

A carefully selected scrap charge to produce the liquid steel that is cast to ingots in moulds or blooms and billets on our highly productive continuous casting machines forms the basis for our tailor-made mandrel bars. The mandrel bars themselves are produced by rolling or forging, then quenched and tempered and, finally, surface-finished by peeling. They are finish-machined on CNC lathes. Then mandrel bars are given a scaled surface or chromium-plated.


We produce mandrel and shaft bars to ultra-tight diameter tolerances. Up to a length of 25 meters, for example, we peel the bar to a dimensional tolerance of not more than 0.05 millimeters. We supply mandrel bars in a large range of sizes and finishes. We assist our customers in the planning of new and upgrading of existing facilities, as well as the planning of full-line solutions that may even include the production of the feed material.

  • Max. dimensional tolerance +/-0.05 mm
  • Lengths up to 25 m
  • Accessory equipment, e.g. piercer plugs

Our supply range

Mandrel bars

Mandrel bars for the production of hot-rolled seamless tubes and pipes:

Diameter Bar length Material Material No.  
80 - 200 mm up to 25,000 mm 28 NiCrMoV 10 1.2740 Request quotation
80 - 150 mm up to 25,000 mm X35CrMoV5-1 /X40 CrMoV5-1 1.2342 / 1.2344 Request quotation
100 - 430 mm up to 16,500 mm X35CrMoV5-1 /X40 CrMoV5-1 1.2342 / 1.2344 Request quotation


Shaft bars

Shaft bars for advancing the mandrel bar during the rolling process:

Diameter Bar length Material  
100 - 150 mm up to 25,000 mm Various grades Request quotation


Piercer plugs

Piercer plugs for producing the hollow:

Diameter Bar length Material  
in acc. with customer drawing in acc. with customer drawing Various grades Request quotation

Surface and end finishes

  • Ground
  • With scaled surface
  • Chromium-plated
  • Finish in acc. with customer drawings
  • Case-hardened

Do you have a question on our Products? Just contact us!

Thank you very much.

We will contact you immediately!

An error has occurred!

Please try again later.

* = required field


Marco Altenhöfer

Sales Director Peeled Bars & CNC