Cutting down HSS planer knives

[mkepke]

I need to buy some spare planer knives for my new planer. Unfortunately, it's not a very common size (15.25" x 11/16" x 1/8").

I did find the right size HSS knives at a good price at Holbren - but 3" too long (i.e. 18") knives.

Does anyone see a problem with shortening the knives by scoring with a grinder, snapping to length, then grinding to finished length and matching the weights on a bench grinder ? Ought to be easy-peasy if I keep the steel reasonably cool, right ?

-Mark

[erasmussen]

If there HSS cutting them should not bother the temper.

[Hill]

Might want to grind a bit and then cool in water just in case. If you start to see any color change, cool it quick. Carbon and alloys are supposed to be like wonderbread, but they do have their limits. If you have a grinder handy, an 80 grit flap wheel helps to keep the temperature down quite a bit

[DaveD]

The info I have seen on machinist sites says you can grind HSS till it gets a low glowing red (1000-1100 degrees F) and not hurt it. Besides in a metal lathe it (the HSS cutting bit) can get 'hot' and stay there for the duration of the cut.

The few HSS cutters I have ground I have used visegrips to hold them and ground hard up to just shy of slowing the grinder down. Sometimes on a HSS lathe bit you have to take a LOT of material off the initial blank to get the shape you want.

if I was doing chisels and gouges though I'd have a much more easy hand and grind lightly.

[thesource]

Mark,
If you have a metal cutting chop saw, use it. Stand the knife up, and cut at relatively quick a steady pace. Go as fast as you can without slowing the blade.
Don't go slow, because that's how the steel gets so hot.
That's how we cut 5/16" thick moulder steel. No special wheel, just a standard 14" metal cutting wheel. We cut through a 2" wide piece, 5/16" thick in about 7-10 seconds.
Your planer knives should take about half that time. Good luck.
PM me if you have any questions.

[mkepke]

Crisis averted.

Holbren responded to me offering to provide knives cut to the correct length, even tho it's not a stock size for them.

Price is better than any I've found at ~$46-ish delivered for 3 @ 15"knives.

-Mark

[Guy in Paradise]

This site has your blades at 15" x 11/16", which would fit, although they might be 1/4" shorter
http://www.planerknivesdirect.com/products.php?cat=10

Here is one that are 15.5" x 11/16", which may or may not fit. http://air-inc.us/planer.htm

And here is a current sale on just the blades that are your size: http://www.belsaw.com/news.html

[mkepke]

Guy - thanks for running a search. Until Holbren, 'planer knives direct' was the best price I found at $60+ship - although I'd never heard of PKD or American Industrial before.

Belsaw doesn't include the 15" knives in their sale, otherwise it would be a very good price indeed !

-Mark

[FredP]

might want to check here. 35-40 bucks a set depending on 3 or 4 knife set. they don't have 15 1/4" but they may cut them for you. cheapest I've found. they beat others I've found by 20 bucks or more per set for my 20" PM. the knives seem to be very good too. T-i HSS

[James Davis]

Originally Posted by FredP

might want to check here. 35-40 bucks a set depending on 3 or 4 knife set. they don't have 15 1/4" but they may cut them for you. cheapest I've found. they beat others I've found by 20 bucks or more per set for my 20" PM. the knives seem to be very good too. T-i HSS

Where?

James

[FredP]

oops! forgot the link.....

http://globaltooling.bizhosting.com/...nife-sets.html