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Stubby Drill Bit Set?
- Thread starter Kroll
- Start date
- Joined
- Apr 14, 2014
- Messages
- 3,140
OK, what is it specifically that you need "screw machine" or "stubby" drills for? I've been drilling holes professionally and for a hobby for over 50 years. I've never owned or intentionally used "machine screw" length drills. I've used jobber length, spotting drills, center drills, parabolic drills, number drills, letter drills, fractional drills, high carbon drills, HSS drills, cobalt drills, carbide drills, and probably a hundred other types of drills.
The closest I came to using "machine screw" length drills is was as a kid working at a GM assembly plant. The job was to fixture and drill holes in the front fenders of GM trucks to attach chrome moldings. Each drill cut a new hole every 2 minutes for 16 hours a day. The drills started out as jobber length, after numerous sharpening's they were reduced to machine screw length, then to stubby length ( less than 1/2" of flutes) and finally became recyclable length. It didn't take all that many days to go from a jobber length drill to being recycled.
The closest I came to using "machine screw" length drills is was as a kid working at a GM assembly plant. The job was to fixture and drill holes in the front fenders of GM trucks to attach chrome moldings. Each drill cut a new hole every 2 minutes for 16 hours a day. The drills started out as jobber length, after numerous sharpening's they were reduced to machine screw length, then to stubby length ( less than 1/2" of flutes) and finally became recyclable length. It didn't take all that many days to go from a jobber length drill to being recycled.
- Joined
- Dec 12, 2016
- Messages
- 493
If you are drilling deep holes in the lathe, starting with a stubby makes in more likely to stay concenteric as it is stiffer and is less likely to walk off path.
Projectnut,you have my eyes open and my ears are ready.I don't know what the difference is other than 10.00 The screw stubby are 94.00 and the jobber are 84.00 So myself I don't know the difference other than price.Machpete and Aukai give my reasons for wanting them. I do like the ideal guys of just buying the tap sizes but I may do that as a bonus purchase when money permits.So far the small projects that I been doing I can see the need for good drill bits,so wanting to get it right this time.Thanks guys for the guidance,with all the good ideals and comments I see that we all take drill bit purchase serious.No more hardware store drill bits for me----Kroll
- Joined
- Sep 13, 2018
- Messages
- 255
A 135 degree tip with four facet grind will do that for you as well. Won't even need a centre drill.
- Joined
- Jul 8, 2018
- Messages
- 880
"need" is perhaps overstating the case. Stub drills flex less than jobber length because the shaft is longer than the flutes (usually 2-3x longer). This is very helpful at the sub-1/4" diameters. They are also useful for drilling steel with a hand-drill, which is something one doesn't do very often but when the occasion comes up it's gotta be done.
It might also be said that when you don't have the optimal drill type for a job, a stubby will get it done without breaking off or ruining the part.
- Joined
- Dec 26, 2016
- Messages
- 2,015
The ones I linked are mechanic's length which have shorter flute length and shorter overall length than a standard jobber bit.