Technological tooling for cold rolling of tubes, sheet and profile

"Institute Tsvetmetobrabotka" offers their services on the calculation and manufacturing of working tooling for the cold pilger mills, including:


  • dies of working rolls
  • – rollers of constant cross section, cylindrical and profile

    – ring type dies

    – half-disk type dies

    – horseshoe type dies


  • mandrels
  • by type:

    - taper

    - curvilinear

    by cross-section shape:

    - cylindrical

    - profilied


  • support rails

Calculation of calibrations and working tooling manufacture


Manufacturing of working tooling.

For manufacturing of tooling for cold pilger rolling it is required a special equipment. Mandrels and support rails are manufactured mostly at standard cylindrical and surface grinding machines with CNC after pre-turning. To manufacture dies of variable cross-section is possible at specialized machines only. The most common of these are "Special cylindrical grinding machine with CNC GG-52" (SMS-Meer, Germany) and "Machine for turning of dies groove for cold tube rolling mills LZ-250 model" (St.-Petersburg plant of precision machine building). Because LZ-250 machine has only recently been upgraded that for finishing of dies grooves the GG-52 machine is most commonly used.



Institute performs calculations of individual calibrations and develops universal programs for automatic calculation depending to Customer requirements. The programs of working tooling profile calculation is fulfilled on the base of EXCEL spreadsheet and allow to make calculations of dies profiles and mandrels for cold rolling pilger mills in which radius of dies groove and value of deformation vary continuously along the working stand stroke length.

In the program, all parameters of rolling tooling necessary for analysis of a given pass schedule and for dies and mandrels manufacture are presented. Crimp section of die groove profile from zero cross section up to recrimp is divided by 40 control cross sections but calibrating section from recrimp up to the end is divided by 4 control cross sections. Output (estimated) parameters are optimized for software of specialized profile grinding machine GG-52 CNC.


Calculation of calibrations and selection of rolling pass schedule.

Initial data for calculation of working tooling calibrations for cold rolling are material and rolling pass schedule. The methodology of calculation is a concept proposed by U.F.Shevakin. Idea is in maximum crimping of shell at the beginning of the working zone and in minimum crimping in calibration zone in which maximum hardening is reached.

Parameters of deformation zone. The first calibrations for cold pilger rolling of tubes were proposed in 1937 by P.T.Emelyanenko. Sweep of dies groove along the comb have been fulfilled on a straight-line low and was as straight line having inclination to the rolling axis corresponding to difference between the radius of shell outside surface and rolled tube. The mandrel also was made with straight-line shape, the taper of which was less then taper of groove comb.

As practice of exploitation showed, in this calibration distribution of crimpings along of crimp zone took place at growing mode reaching the maximum at the end of crimp section, as a result under normal width of die its overflow was occurred but under increasing of die width the accuracy of rolling was decreased. Linearly tapered calibrations, used earlier in hot pilger process have been work out without considering of material hardening in the process of cold deformation. As a result, at the end of crimp section, tube cracking due to excessive crimping was occurred. It became obviously that increasing of cold pilger rolling effectiveness can be reached by creation of such regime of crimping along the length of crimp zone which would facilitate to changing of material properties with increasing of deformation level.