This job came along and it reminded me of a recent thread about using carbide on 4340. This material is 4140 which is fairly close as far as machinability is concerned.

Also to demonstrate that a nearly 100 year old machine still has a place in a for profit, modern(??) machine shop.

Material is 17" diameter 4140 annealed that needs shafts for 3-15/16" bearings on both ends. Not my style of engineering, but I wasn't paying the bill so.... Started with 4 pieces with a combined weight exceeding 6000 lbs. finished with 4 pieces that weighed 647 lbs. each, that calculates to 8 barrels of chips weighing approx. 3500 lbs.

Depth of cut varied from 1/4"-3/8", feed rate approx .025"-.030". Spindle speeds varied between 66 rpm and 88 rpm, with fpm varying between 200 and 350. Motor rated horsepower is 20 hp, Kennametal calculator says this cut takes 25-27 hp. which is roughly confirmed with amperage readings. Photos to follow.

The last photo shows the four parts ready for heat treating and final machining which I don't get to do this time.

Also to demonstrate that a nearly 100 year old machine still has a place in a for profit, modern(??) machine shop.

Material is 17" diameter 4140 annealed that needs shafts for 3-15/16" bearings on both ends. Not my style of engineering, but I wasn't paying the bill so.... Started with 4 pieces with a combined weight exceeding 6000 lbs. finished with 4 pieces that weighed 647 lbs. each, that calculates to 8 barrels of chips weighing approx. 3500 lbs.

Depth of cut varied from 1/4"-3/8", feed rate approx .025"-.030". Spindle speeds varied between 66 rpm and 88 rpm, with fpm varying between 200 and 350. Motor rated horsepower is 20 hp, Kennametal calculator says this cut takes 25-27 hp. which is roughly confirmed with amperage readings. Photos to follow.

The last photo shows the four parts ready for heat treating and final machining which I don't get to do this time.

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