Parting with cardide tools

[Jasonb]

Put a bit of shim stock between the blade and the tool holder. Take the bottom thickness off the top thicknes and divide by 2 to get the shim thickness.

J

[mgj]

Loply - there is a reason for that taper. It means that the sides of the blade don't rub. If you have a straight blade you have to have it set EXACTLY vertical and even then on a deep cut it can jam.

Tapered is good, and Jason has the answer - I have to do the same when sharpening, though my holders are for tapered blades.

(There isn't necessarily that critcality about the vertical on indexable blade systems, because the tip is wider than the blade - and they reduce side contact area to a very small amount that way. We can't do as well as that with blades, but we can make sure the sides don't rub)

[djc]

Well the HSS blade arrived but unfortunately it is tapered on both sides and so won't work in my Glanze holder!

It is more likely to be hollow ground than a straight taper. It is very easy to fit to your holder: just drill and tap for two little grub screws near the bottom of the holder. Install with some PVA adhesive (acts as a 'thread stiffener' rather than 'thread locker') and adjust out until the top of the blade is horizontal (or until there is clearance on both sides when checked with a square). Wind in fully before reinstalling the carbide-tiped tool.

GH Thomas' books go into this is great detail and are perhaps the best advice available on HSS parting.

The Glanze stuff is generally very good, though the inserts themselves in my experience are poor. Parting is a bit of a black art and for carbide, I would buy a proper brand name holder (Iscar, Sandvik, Korloy, etc.) every time, the thinner the better. Most of the 'hobby' level stuff starts at 3mm which is a bit wide (and wastes stock).

[Scuba1]

I use a Kenametal holder and different tips from the same company for it. Having said that, I don't as a rule work with mild steel as I get stainless for free but in Stainless, ally and brass the tips work very well as long as I stay close enough to the chuck.

ATB

Michael

[johnf345]

If possible support the workpiece with the tailstock - however short it is.

[Mike4]

That style of parting blade is so expensive I have pretty much put mine aside.  That was after having broken both ends of one blade and buying another blade which by then cost me more than the original blade and holder.

BTW, I ground the end of the broken blade to make a regular parting blade, it works so well it makes me wonder if I will ever buy any more chips!

I only use carbide parting tools as I have had several HSS cutters jam and destroy an almost completed part,(not good when a customer is waiting).
Yes they do break if not sharp or the tool holder is not square to the part being cut, also I find if you are going to be going in deep a little sideways clearence helps let the chips out and not bind.

Also some steels are full of tough spots and can create havoc , avoid customer supplied  material if not sure.
My 02c worth.

Michael