Molding MDF with HSS knives

[Jaspal Singh]

Hello everyone,

Like most people I have been cruising the forum checking the comments and questions that everyone posts. Its been a lot of help to me so far.

Currently I am in the middle of changing the basic casement and trim that was installed in my house, and now have a need for custom knives to be made. I am using a shop fox G0488 molder/planer and have already used it to mill some chair rail from MDF using knife profiles that I purchased from grizzly along with the machine. What I didn't know at the time and didn't realize till I started doing searches on knife grinding that carbide knives are recommended for MDF.

The knives that I did purchase are HSS knives and I ran about 200 feet with them and didn't really have any issue other then burning cause the feed rate was too slow. What I would like to know if other members have used HSS knives to cut MDF molding. The total run that I will need is about 400 feet and then I wont be using them much after that. I am avoiding carbide cause the estimate that I was given was $70 per inch, versus $20 for HSS:eek: .

Thanks

Jas

[David DeCristoforo]

You can ise HSS but it will dull quickly. Carbide will not be as "sharp" but it will hold it's edge much longer. But, for a 400 foot run, I would not invest in carbide.