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brian Rupnow
12-03-2010, 08:04 PM
Guys, I'm having valve seating issues with the small I.C. engine I have been building, and I want to machine a valve seat "truing" tool like the one in the picture, out of drill rod. This is small---the minor diameter is .093"---the major diameter is about 5/16". I have carbide lathe tooling to turn the diameters, but I only have HSS milling cutters. Can I make the 4 "plunge" cuts which form the cutting facets with an HSS end mill into the drill rod? I will harden the drill rod after the machining is finished.---Brian
http://i307.photobucket.com/albums/nn294/BrianRupnow/VALVESEATCUTTINGTOOL.jpg

Toolguy
12-03-2010, 08:16 PM
Yes, HSS end mills and lathe bits work fine on drill rod. I make things that way all the time. Keep the spindle speeds low so the drill rod doesn't heat up and you're good to go.

DFMiller
12-03-2010, 08:56 PM
Machine-ability of drill rod (A1 or O1) is poor if I recall. I think I checked earlier in the week and its about 40% in the table I looked at. I would agree based on my experiences. HSS will work fine.
Dave

macona
12-03-2010, 09:15 PM
O1 machinability is pretty darn good. We use it for all sorts of stuff because it is cheaper than ground rod. You can use any cutter to cut the stuff.

DFMiller
12-03-2010, 09:25 PM
I will double check my book. I think I was using the black book. Its does not machine as nice as 12L14. At least not on my crappy machine. I will defer to the experts.
Dave

brian Rupnow
12-03-2010, 09:41 PM
Is it really worth making a tool to cut one valve seat!!! I'm torn here. I really don't want to take the head off this engine again after tomorrow. I will definitly make a new valve from drill rod , because the stem on the intake valve is undersize. I do have a container of Permatex valve lapping compound, and the seat (valve cage) is made of brass. I can do a heck of a lot of lapping in the time it would take me to make a valve seat cutting tool like George Britnells. I'm not sure I'm a total putz at filing and honing, but I'm light years away from Georges abilities. I think the plan will be #1---Make a new valve #2--Lap the valve. #3---Lap the valve some more. ---#4 Then lap it a bit more. #5--Put some permanet marker on it and do the concenticity test. #6---Pray----#7---Reassemble engine. Thanks for your answers, gentlemen.

deltaenterprizes
12-03-2010, 09:51 PM
W-1 is the best machining I have found.

Toolguy
12-03-2010, 10:38 PM
Actually 0-6 is the freest machining tool steel. The common drill rod materials from cheap to expensive are W-1, 0-2, A-2, D-2, S-7. They can all be easily machined with HSS. Not as easy as low carbon, but not hard to do.