Is it just me......

Raymond Richard

Raymond Richard

Joined
Jun 17, 2001
Messages
5,705
For the smaller knives I make I use a 6 32 thread for my ring nut. For some reason I keep breaking the taps for this size. A 1/8" drill is just a fuzz to big but the next size smaller is 7/64. I even went and bought the drill and tap set and it comes with a 7/64 drill bit. I use taping oil and snap the tap just about ever other time I do it. Is there a numbered drill bit that will work better?
 
On my drill chart between 1/8 and 7/64 you have # 35-31, 2.8mm-3.1mm, N 6/40 and M 3.5x0.6




sunnee
 
That sounds peculiar, Ray. I say this because I know your knives are really nice and they reflect your skills. So therefore, I know you know how to tap properly. The only thing I can ask is if you are using a 2-flute tap in steel?

A 4-fluted tap is recommended for use in steel, and I recommend a simple tap made from High Speed Steel, and not the Ti-coated or cobalt taps, as these tend to be much more brittle. Also, if you can get taps made by Cleveland Twist Drill, get them. I'm having very good luck with those.

Last but not least, I occasionally have to tap threads into a very tight hole. I do this when I want to be absolutely sure the threaded percentage is close to 90% or better. On the smaller taps like 6-32, I use the smallest T-handle tap wrench I can get - not the straight handle. This gives me more "feel".
 
Jeff, Thanks for the tip, I'll see if I can find some 4 fluted and see if that makes a difference. I'm sure the amount of material is making a big difference with the smaller taps since its usually 1/4 to 3/8". Maybe I'm just asking to much.
 
Ray, get a set of number drills, there are several between 1/8 and 7/64. I use the number drills 20 to 1 over the fraction drills. Gib
 
Gib, I do need to do that. Every place thats real close to me just carries fraction bits. For the most part they work just fine, it just this one size that gives me problems. Just happenend to think there's a hardware store east of me that may have what I'm looking for.
 
Gib, I'm really not wanting to buy a whole set of bits, just a few of what I'm needing. As far as I know HF only carries fraction bits in packs. I'll find something that will work for the 6 32 or just go to the next size larger.
 
I bought a set that has about 130 bits (don't remember how many, actually, but it's all the fractional, numbered and lettered bits from about 60 to half inch) that cost $30 on sale at HF. Whenever I break one I just replace it, usually can find the numbered/lettered bits at the neighborhood hardware store (forget Home Depot, they cater to the DIY homeowner crowd only). It's been truly fine to have every bit I ever need, no matter what...

Dave
 
Buy a better tap, and hopefully you are reversing the tap as soon as it binds?????
Are you doing it by hand or using a battery drill etc??

Make a fixture to keep your tap straight.


Using a bigger drill will only help.


BTW-Those Chinese drill bits REALLY suck!
 
I'm using all the proper tools and also reversing when I get bound up. Everytime I have bought a tap with the drill bit in the packet they have always worked just fine. Just seems to be the 6 32 that gives me problems. I'll get a few number bits and I think my problem will be solved. Guess I need to get some 6 32 taps since mine are all broken...
 
Ray if you are tapping up to a 3/8" thick piece of steel
it's very important that you follow the hole exactly
I'm sure you know this anyway but I'll add this for guys that don't know..
if the tap is started and misaligned at the least
it will be cutting the side of the hole on the other end pretty hard and in turn
binding and trying to bend to follow the hole if you know
that I mean.
I use a v/speed drill and don't like backing out until
it's cut, when using a taping head you don't back up untill the hole is cut
and they work fine. the key is
alignment,
a good cutting fluid,
the right size tap drill
and a sharp tap
a soft steel helps too..

I'm not sure what way you're tapping but if you are
drilling on a drill press at least start the tap from the spindle
before moving the part from where you drilled the hole
making sure you have it aligned.

when I was a Machinist I made a spring loaded center to used
on a drill press or Mill
for doing it by hand this would put a
little pressure on the tap
handle and center it while taping.. Rene just posted one he made
or purchased just a short time ago if I you're interested in that.
Just 2 more cents and I hope it helps

:) ;)
 
I had trouble breaking 1-72 taps threading ti. I knew that alignment and side pressure was the culprit. I used a spring loaded center punch to apply the smooth pressure and alignment that I needed. First I made a center drill mark in my tap wrench top. I took the top off the spring loaded center punch and chucked it in the drill press, with the spring compressed comewhat. I then brought the tip of the center punch into the center drill mark on the tap handle, and now I could turn the tap handle without having it wobble. Worked fine, was able to tap the other liners without breaking any taps. I hope you can understand what I am saying.
 
good job Don that's it..:D

good tap wrenches have that center in the back most the time anyway.
it was used to lathe the tap tool out.
 
Dont laugh but I dedicated one of the $39.00 drill presses with the motor removed and the return spring backed off. I can use the handle to start the tap while turning the pulley by hand. It has enough leverage and feel to turn it back and forth when it binds. The alignment is straight so there are no wobble problems. Didnt want to spend the bucks for a threading machine or a tapping head.
 
I checked within a 10 mile radius of my house for taps and numbered drill bits. Found a 6 32 tap that calls for a number bit at one place but they don't carry numbered bits. I just don't under stand why they would have one and not the other. Guess I'll have to go downtown.....
 
Originally posted by Bruce Bump
Dont laugh but I dedicated one of the $39.00 drill presses with the motor removed and the return spring backed off. I can use the handle to start the tap while turning the pulley by hand. It has enough leverage and feel to turn it back and forth when it binds. The alignment is straight so there are no wobble problems. Didnt want to spend the bucks for a threading machine or a tapping head.
Click to expand...

Bruce a great Idea
even if one isn't dedicated, the small ones like that are easy enough to take the belt off and you don't need a lot of spring presser
to use it as a drill press anyway. good one..:)

Ray you can use a 7/64 (.1094)Tap Drill for a 70% Thread
with the 6-32 tap

look here for the different bits you can use for any of the taps.
http://www.knivesby.com/drill-tap-chart.html
you have different classes of fits too,
a class (A) fit is a tight fit, you need a wrench or screw driver
to insert or remove the bolt or screw. a class B or C should be OK
 
Originally posted by Raymond Richard
I checked within a 10 mile radius of my house for taps and numbered drill bits. Found a 6 32 tap that calls for a number bit at one place but they don't carry numbered bits. I just don't under stand why they would have one and not the other. Guess I'll have to go downtown.....
Click to expand...

Best bet is to get an MSC or McMaster-Carr catalog, Ray. I think MSC has a wider selection, but McMaster has them beat hands down for service. In the 15 years I've been an industrial mechanic, McMaster-Carr has never screwed up one single order. They also offer discounts on taps and drills if you buy package quantities, which for the sizes we knifemakers use is usually 12 to a pack.
 
You must log in or register to reply here.
Back
Top