Simple forms can be machined easily on milling machines and ground on the tool and a cutter or profile grinder .Punches and dies are marked, milled or filed, hardened and ground or polished. Spherical end mill can be used to obtain the desired corner radii in the in non-cylindrical dies and punches. These radii and milled surfaces of the dies are finished manually using tiny grinding wheels of a variety of shapes. Human skill becomes an important in finishing less accessible crevices.

Irregular forms can be finished by spark erosion machining. The electrode is a male mirror image of the die to be eroded. It is necessary to use a number of electrodes with only the finishing electrode being an exact mirror male replica of the die. Roughing and semi finishing electrodes are smaller. As the electrodes wear considerably during erosion, worn out electrodes can be used for roughing.

Bending tools which are stressed less than 80 N /Square mm can be of cheaper ,easier to machine case hardening steels .Bending and forming tools need not be as hard as the cutting tools. Punches and dies can be hardened and tempered to HRC 55-58.
The manufacture of the tooling is carried out in the tool room department, Prabha Dytek Ltd. The detailed process plan for manufacturing of tools is as follows.


1. After receiving the design from the design department, planning department will decides the work movement of the tool.
2. As per bill of material raw material will be procured according to planning date.
3. As per detail drawing all the raw material will be pre machined.
4. As per planning date each job will be sent to respective of their operations. Ex: Round items----turning, Flat items----milling.
5. As per detail drawing spotting work will be carried out.
6. Flat items sent to maintain right angle grinding for spotting reference.
7. According to drawing all drilling work has to be done except dowel holes in soft material (Dowel holes to be transferred after suiting).
8. Punch and dies to be prepared for heat treatment.
9. After heat treatment all dowel holes to be checked for dowel pass if the dowel is not entering easily then lapping is to be done and sent to grinding.
10. Die set was prepared first.
11. All punches and dies are mounted on their respective places.
12. After mounting the punches and dies alignment will be carried out in any one of the following three methods
-Using blue.
-Using shim.
-Using light.
13. After accurate alignment tool will be sent for trials.


The process capability (or machine tool accuracy study) of a machine or tool or manufacturing process can be defined as the minimum tolerance to which machine can possibly be expected to work and produce no defectives under the specified conditions.


Process capability analysis is a vital part of an overall quality improvement program.
Process capability analysis consists of:
  • Measuring the process capability to find out whether the process is inherently capable of meeting the specified tolerance limits.
  • Discovering why a process ‘capable’ is failing to meet specifications.
  • Assist product developers / designers in selecting or modifying a process.
  • Assist in establishing an interval between sampling for process controls.
  • Reducing the variability in manufacturing process.
Thus process capability is a technique that application in many segments of product life cycle, including product and process design, and production or manufacturing.