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Why are spotting drills so expensive?

Cole2534

Diamond
Joined
Sep 10, 2010
Location
Oklahoma City, OK
I don't understand why these things are so pricey.

At Maritool a #3 center drill is $5.07, but a 1/4" spotting drill starts at $16.12.

What am I missing?
 
could someone post the tipp of a spotting drill, please? (i just bought some and i dont like them.)
 
Many spot drills are solid carbide (extra rigidity in the base material) as opposed to HSS center drills (supposing there are solid carbide center drills but never seen these up close & in person).

This drives up the price.

IMO its worth the extra for solid carbide, as it won't wander when you are trying to spot-up a broken bolt, slightly inclined surface, etc. I think the tip is a lot tougher than a center drill, that is, as long as you don't drop it, free-fall style, from the chuck! :eek:
 
There are carbide center drill which I have used but did not really have good luck with them. I prefer a HSS center drill or even a HSS spotting drill. One problem that I have is the angle of spotting drill I use is 45 Deg. and drills are not, so sometimes it will notch the cutting edge on drill. Im not sure what price range is on the spotting drills we get from MSC.
 
One problem that I have is the angle of spotting drill I use is 45 Deg. and drills are not, so sometimes it will notch the cutting edge on drill.

Best info I have (and what I use) are 120deg included spot drills which interact nicely with 118deg HSS drill bits and provide a nicely fitted "temporary locating cone" to get the first drill bit on location. I would think the 90deg would provide some of these benefits but could wander if one drill edge before the other "digs in" a bit on the sharp spot hole edge.
 
I can't figure out why the things are as expensive as they are, I also can't figure out why they all aren't double enders. It is the ultimate tool
that lends itself to being a double ender. Center drills are double ended, not spotters. Sure would be nice if they ground a spot drill on
the back end of endmills. I'd pay a few more dollars for that.

I've pretty much given up on spot drills, especially carbide ones, I've got piles of them here that are all chipped up. I've got quite a few HSS
spotters too, and they seem to last and last. I used one 5/8 for like 3 years until an oops moment.

I don't get the geometry of them either, really not very good.

Lately, I haven't been spotting anything, either just slam the drill in, or I've been piloting with an 1/8" carbide drill(or 3/32), that works great when
drilling something that can't take a lot of down pressure.
 
I checked a .375 spotting tool vs a .375 screw macine drill, spot about 31.00 drill about 16.00. Seems to me it should be cheaper to grind the spotting tool. Both tools are cobalt and the same oal.. I don't get it.
 
I had a job that I posted about here that I had broken a number of 1/4" drills and an end mill on the previous time I ran it. Following the suggestions here I got a price for 1/4" spotting drills of over $30 each, I couldn't believe how expensive they were. I ended up buying 4 screw machine bits for about $6 each and drilled all the holes with one or two bits. I was lucky and didn't break any but I did take the corners off the bit, which I can sharpen later or I can afford to throw away a dull $6 drill bit.
 
Not worried about the price as an operator but all I always use a 120 degree solid carbide garr spot drill for an hss drill and get about. 0005 -. 0015 runout depending on the drills shape. And a 130 degree when using a titex or nachi 135 degree drill and hold. 001 with a same drill for a whole job up to 100 parts. Can't do that with a center drill.

Also made up my own little formula for spot drill depths. Spot drill diameter /3 then take 75 percent of that number. Don't know anything behind why but it works real well for me.
 
In new Enco hot deals flyer that I got today ,they have Melin solid carbide 1/4 dia 2 flute end mills that can be used for spotting for $12.99 to $16.99 depending upon point angle. May 4th.
Jim
 








 
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