PUNCHING AND STAMPING: How to compare production cost
(Article by Andrea Dallan)
“ A short guide to identify the technology from among those available, for the lowest possible production cost, according to the number and type of parts to be produced ”
Fig. 1
Sheet metal products
produced by punching
from sheet, coil or by
hard tooled stamping
(casings for lighting
appliances).
The aim of process engineering is to identify the least expensive production cycle to make a product.
A sheet metal product follows a cycle that starts from raw material, goes through shearing (punching, blanking or laser cutting) followed by forming (bending, stretch-forming or embossing, rollforming).
The cutting technologies by punching and stamping (fig. 1) will be taken into consideration in these pages due to their similarities.
The purpose is to identify the technology from among those available that, in a specific working situation (number and type of parts to be manufactured) completes the production at least cost. We will then analyse these technologies to define the typical costs of each one, firstly identifying the three factors that added together give the production cost:
- raw material
- tools
- hourly cost of the machine
The last value being multiplied by the hours necessary for production.
To calculate the hourly cost of the machine, another four component factors will be analysed:
- labour cost connected to machine operation
- maintenance cost
- energy cost
- cost of plant amortization
Lastly, the production costs either with sheet punching machines or coil punching machines will be compared. Likewise for the production costs with coil punching machine and press with die. This last part will also provide useful formulas, given the type of product and required quantity, for identifying the technology to obtain production at the lowest cost.
"Punching and stamping: how to compare production cost."
Article taken from "Lamiera" Magazine: October 2005