I have heard the same story so many times: precision surface grinding is obsolete. The use of manual surface grinders is a thing of the past, etc.
The odd thing is that there are always injection mold makers standing there performing precision surface grinding when this is said by the salesman who is showing clients through the shop!
It is true though that WEDM has replaced a huge amount of precision surface grinding. Anyone I know is very thankful for this! Not many people miss the days of elaborate setups required for contour grinding, for example.
How is precision surface grinding used in Plastic Injection tooling?
First, there should be a distinction between manual surface grinding and hydraulic surface grinding. For the purpose of this article, manual surface grinding means the grinding of mold components, such as core pins, slides, lifters, core and cavity details, etc. Hydraulic surface grinding refers primarily to squaring up blocks and plates for subsequent machinings, such as CNC milling.
Some common applications of manual surface grinding are:
- Finishing shut-offs on core and cavity blocks
- Making lifters
- Finishing core pins and inserts
- Electrode manufacture
- Ejector pin grinding
- Finishing slides and cam blocks
- Squaring up small inserts and blocks after heat-treat
Why apprentices should do a lot of precision surface grinding