Can HSS endmill mill down Chinesium tool steel?

[stioc]

I got a Chinese 1/2" carbide insert tool bit holder for my lathe (parting tool actually), unfortunately it sits about 2mm (.08") too high from the centerline even with my AXA tool holder cranked all the way down. Before I dull or break my endmills thought I'd ask if these cheap tool bit holders can be milled down with HSS or Cobalt end mills? If not, what's the best way to mill it fairly flat? I have a bench grinder, 1" belt sander with a 5" wheel as well as a Dremel flex shaft toolpost holder for the lathe. As I'm thinking about it may be holding the tool bit in the 4 jaw chuck and using the Dremel flex shaft with an abrasive wheel would be better? IF I can hold it in it the chuck somehow.

 

[benmychree]

Try it with a file, if it files fairly easily, it will cut with an end mill at reduced speed, I'd start at about 30-40 FPM cutting speed, use cutting oil. I just recut 5 tool holders today, but surface ground them about 1/8" undersize to 1/2". I have milled others, but they were pretty hard, I used a carbide indexable end mill, that at reduced speed.

 

[darkzero]

I agree with John, test it with a file. Some China tooling is not that hard & only case hardened. I've done it with a HSS-Co end mill, didn't last long but got the job done. I've tried milling some quality USA hardened tooling before, it just laughed at the HSS end mill.

I'd just buy a carbide endmill, $20 or less shipped from ebay or less depending on the size.

 

[martik777]

These work well: https://www.aliexpress.com/item/327...lgo_pvid=aab84b0b-cf84-425c-8cdd-fa24cb5fb6a7

I also made an angle grinder grinding wheel fixture I use on the mill to "surface grind" hardened material.

 

[stioc]

Thanks all, I'll give those suggestions a shot. I've been meaning to buy one of those indexable carbide endmills for a while so may be this project makes it a 'must have' lol

I'm surprised no one said to use the Dremel in the toolpost.

 

[MrWhoopee]

I just use a small flycutter with a cheap brazed carbide in it. Works every time.

 

[RJSakowski]

If the difference is small, Shars sells an 250-101-XL tool holder for 5/8" tools on an AXA QCTP. The floor of the slot is slightly lower than the standard AXA tool holders.

 

[stioc]

I just use a small flycutter with a cheap brazed carbide in it. Works every time.

I've done the same thing with the left hand indexable carbide tool bit in my flycutter with excellent results. However, after seeing some carnage from unbalanced tools like the flycutters I reallly try not to use it if I can help it. A knock off of the Tormach shear hog style is what I want to buy.

If the difference is small, Shars sells an 250-101-XL tool holder for 5/8" tools on an AXA QCTP. The floor of the slot is slightly lower than the standard AXA tool holders.

That's good to know, thanks! If I can't skim a few mms off of the tool bit I'll get one of those tool holders.

 

[stioc]

I'd just buy a carbide endmill, $20 or less shipped from ebay or less depending on the size.

Will, do you have a recommendation or have had good luck with any particular ones?

 

[martik777]

I linked a carbide end mill in post #4 (the 6mm for $4 works great):
https://www.aliexpress.com/item/32798922280.html?spm=2114.search0604.3.37.1dea3b11dh1gHT&ws_ab_test=searchweb0_0,searchweb201602_6_10065_10068_10130_10547_319_10059_10884_317_10548_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_537_536,searchweb201603_52,ppcSwitch_0&algo_expid=aab84b0b-cf84-425c-8cdd-fa24cb5fb6a7-5&algo_pvid=aab84b0b-cf84-425c-8cdd-fa24cb5fb6a7