Line boring hss/carbide

[Drcatwrench4]

I just purchased a set of line boring equipment and I have a very very small background in machining. I come from the welding/fab/mechanic world. I was wondering, what grade hss should I look for to cut hand welded bores? What grade and style carbide should i also try? And the big question is where's everyone buying their carbide/hss from online?

Thank you in advance!!

 

[Moper361]

A long time ago on the mines we used to use a line boring unit made by Hoffman engineering ,we use it for line boring bucket swivel pins on the O &K face shovels approx 300 mm diameter pin .it had a auto rotary mig welding set up for building up the hole using flux core mig wire ,and then from memory as this is about 20 years ago a carbide tip in a tool holder was used for the machining nothing really special from memory .hardest part was getting the weld correct as perocity used to be a pain in the such humid and damp climate and the welds were a long duration if you can emagine a pin about 300 mm in diameter and width about the same 300mm there was a lot of weld to cover this area ,once it was a good weld the machining was quite easy .

 

[Tony Wells]

I need a line boring rig, for the same type of work. May have to build something. I don't think I am going to try to build an auto-MIG though.

If your weld turns out properly, you can go straight to carbide, but get with the mfg and inquire about "toughness" on the inserts you use for roughing. They probably would be different from the grade used for finishing, once you get a smooth, round bore. Same basic approach when selecting your HSS. You need a tough, forgiving grade to take the abuse of roughing the weld, then a harder but less forgiving tool for finishing.

As far as online buying, I'll leave that to the other folks. I use a local supplier primarily, or if they can't help me, MSCDirect.com gets most of my business.

 

[Moper361]

I need a line boring rig, for the same type of work. May have to build something. I don't think I am going to try to build an auto-MIG though.

If your weld turns out properly, you can go straight to carbide, but get with the mfg and inquire about "toughness" on the inserts you use for roughing. They probably would be different from the grade used for finishing, once you get a smooth, round bore. Same basic approach when selecting your HSS. You need a tough, forgiving grade to take the abuse of roughing the weld, then a harder but less forgiving tool for finishing.

As far as online buying, I'll leave that to the other folks. I use a local supplier primarily, or if they can't help me, MSCDirect.com gets most of my business.

The weld if done properly and turned out ok the machining was quite easy and the weld was veey even using a machine to weld so from memory carbide was pretty much all we used .I was quite a handy peice of equipment not overly difficult to set up and use .to be honest someone with decent skills could make up the auto welding part also just using a standard wire feeder mig .

 

[Tony Wells]

Some of the pins and holes I work with are a little smaller than your 300mm though, some on the order of 100mm. I sometimes, if the part is small enough, use my horizontal mill as a boring mill to clean up the hole and make it a standard size, and simply make a sleeve/bushing and have it carburized or nitrided. That way I can usually get it out and replaced without too much bother, and just replace the pin. But many of the parts are far larger than I can put on the table. Plus there is the R&R and transport on big parts. I don't much care for machining parts that weight 1500+ Kg in the first place.

 

[Moper361]

Some of the pins and holes I work with are a little smaller than your 300mm though, some on the order of 100mm. I sometimes, if the part is small enough, use my horizontal mill as a boring mill to clean up the hole and make it a standard size, and simply make a sleeve/bushing and have it carburized or nitrided. That way I can usually get it out and replaced without too much bother, and just replace the pin. But many of the parts are far larger than I can put on the table. Plus there is the R&R and transport on big parts. I don't much care for machining parts that weight 1500+ Kg in the first place.

Yes large parts are a pain ,the bucket and arm pins we used to do onsite in the mine with the face shovel parked were it stopped lol great fun it was setting up that lot out in the open .I can understand yes 100mm would be limited for a auto weld unit and like you say just machine it out with portable boring unit and fit oversize bush is a much easier approach Tony ,What are you working on diggers and loader buckets ? We also used to bore the artic on some large front end loaders cat 994 and grader arctics these were a better job as you were in the comforts of the workshop .

 

[Tony Wells]

Yeah, excavators, skid steer loaders, swivel loaders, scrapers, draglines, dozers, and about a dozen grinders such as a Hogzilla. Different makes, but we have one Hogzilla. It's basically a mulch plant where they take in tree debris and grind it in various grades to make mulch and resell it. The state highway department buys lots of it. Specialized dirt I call it.