Advice Picking cutoff blade for my BXA7 holder

[jerholz]

The original HSS blade that came with the holder I bought 30 years ago is finally getting close to being too short to be re-ground, so I started looking for a new one. If I buy the P-3 1/8" blade from Aloris, It's $30, plus $6 handling plus $18 shipping. The other option is to go to a carbide insert blade (SGIH 26-4C-B7) and a pack of inserts for in the neighborhood of $230 all up from Aloris.

So, the questions I have are:
- Are the carbide inserts going to be a big improvement over HSS?
- If so, any advice on which inserts to buy (there are many)
- Any recommendations on places to buy them other than direct from Aloris or other brands I should consider that are compatible with the BXA7 holder?

I'm an amateur machinist at best. My lathe is a Hendey 12x30 gear head (top speed 1198 rpm). I mostly work with either aluminum or mild steel, occasionally stainless steel. Parting off is always tricky, so I'm not opposed to spending some money to improve my odds of success. I switched to carbide insert turning tools some time ago and I really like those.

Thanks in advance.

 

[Joe Gwinn]

I have both the Aloris BXA7 with HSS blade and a SGIH 26 insert in an Iscar blade. (I also have a 32mm bigger brother of the Iscar.)

Basically, I don't use the steel blade much any more. This on a Clausing 5914, which has a L00 spindle, so no unscrewed chucks chasing me around the shop.

The Iscar blade is in a Dorian BXA holder which is configured to be used upside down, and I do cutting off with the lathe running in reverse. This very much stabilizes parting off - no self-feeding leading to disaster.

 

[DanASM]

Your machine might be a little slow and light for carbide on the parting tool.

I have an iscar do grip that I really like to use over .175" diameters. They chip below .175" due to lack of SFM.

I run Tantung Blades that are old school, but work great. T15 Works great and any Cobalt (M35, M42) will work well and can be sharpened like you have been doing it.

Carbide is expensive and can break easily if your not running it in the right parameters. If you can get a brazed carbide blade on ebay to try out and see if you can make it work, that would be a good way to find out if your machine can take it or not without spending much.

 

[L Vanice]

If you want high quality NOS P3 HS blades, you should jump on this deal quick. Five Empire blades for $40. If they were P3N (3/32" thick), I would have bought them for my Hardinge vertical cutoff holders.

(5) Empire 11/16" HS Cut Off Blades, #P-3 | eBay

Find many great new & used options and get the best deals for (5) Empire 11/16" HS Cut Off Blades, #P-3 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Larry

 

[Bill D]

I agree look at ebay for old USA made quality blades. I like the tee type. They seem easier to hold vertical. I use a chainsaw grindstone to put a slight concave on the top cutting edge. The axis of the stone is parallel to the blade length so the chip curls inward and clears the cut.
Since one HSS blade has lasted you 30 years I think going to carbide will be a learning curve that is not worth your time.
Bill D

 

[L Vanice]

I agree look at ebay for old USA made quality blades. I like the tee type. They seem easier to hold vertical. I use a chainsaw grindstone to put a slight concave on the top cutting edge. The axis of the stone is parallel to the blade length so the chip curls inward and clears the cut.
Since one HSS blade has lasted you 30 years I think going to carbide will be a learning curve that is not worth your time.
Bill D

Empire P blades do have a concave grind on the top and sides. The blades and holders were designed and patented by Luers decades ago and Empire had the Luers license to make and sell them. The older Empire products have the Luers name on them, probably dropped when the patent expired. The Chinese copies that claim to be P blades may not follow the Luers design. I bought some P blades from Shars years ago that were not even the correct height to fit an Empire holder and some others were not even T-shaped.

There are some cheap (Chinese?) P3 size insert-type holders on eBay, but I have never bought one and cannot say if they work at all. But they would be a lot less than $230 if you want to try them out.

Larry

 

[jerholz]

If you want high quality NOS P3 HS blades, you should jump on this deal quick. Five Empire blades for $40. If they were P3N (3/32" thick), I would have bought them for my Hardinge vertical cutoff holders.

(5) Empire 11/16" HS Cut Off Blades, #P-3 | eBay

Find many great new & used options and get the best deals for (5) Empire 11/16" HS Cut Off Blades, #P-3 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Larry

Thanks for tip. I jumped on that deal quick.

I may explore the carbide option later, but I think these will work for me for a while. Thanks for the replies.

Jerry

 

[Joe Gwinn]

Your machine might be a little slow and light for carbide on the parting tool.

My 5914 is about the same size as a Hendy 12x30, and I use carbide all the time, both inserts and brazed. And also lots of HSS.

Big problem with inserts is cost, and physical size when boring.

I have an iscar do grip that I really like to use over .175" diameters. They chip below .175" due to lack of SFM.

Which specific Iscar item? I don't have problems with carbide breaking if too slow. Can get build-up though.

I run Tantung Blades that are old school, but work great. T15 Works great and any Cobalt (M35, M42) will work well and can be sharpened like you have been doing it.

Tantung is good stuff.

Carbide is expensive and can break easily if you're not running it in the right parameters. If you can get a brazed carbide blade on ebay to try out and see if you can make it work, that would be a good way to find out if your machine can take it or not without spending much.

Insert carbide is expensive for sure, especially when not running production.

 

[dian]

just go to aliexpress, get a 2mm, 3mm and 4mm holder for $20 and a box of insert of each size for $10. my chinese 3-in-1 has under 500 lbs and handles them just fine.

btw, run them fast (at normal carbide speed), no need to slow down and loose time.

 

[Zeuserdoo]

You will never get a high enough SFM when parting to center with carbide at your top speed, unless you are parting Inconel or something. I'd stick with the HSS.