How To I’m having some issues making pin holes.

S

steve.15

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Sep 19, 2024
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I’m doing fine on everything except for drilling holes. I bought a brand new drill with new bits, but it just won’t penetrate. It only makes a minuscule indent. Any advice would be much appreciated as to what I’m doing wrong, thanks.
 
what type drill, steel and bits? Drill press or hand held drill! Cobalt or HSS drills? Is the steel hardened or annealed?
 
Assuming you are not trying to drill hardened steel, make certain your drill is rotating in the correct direction. If the steel is hard, try masonry bits with carbide tips.
 
Welcome Steve. Fill out your profile so we know a bit about you and where you live.

A drop of moly lube or tapping oil also helps.
Good bits are a game changer for most folks. A full set of good quality # drills, letter drills, and decimal drills costs $100-150.
What is sold at the hardware store won't last long.
It is cheapest to buy the sizes you use in 6-packs from an industrial supplier like McMaster Carr than to buy a whole set ... unless you use them for other shop work.
Bits need to be resharpened regularly for our kind of use, but many just consider them consumables and throw them away when dull. A suggested starter group would be six each of 1/8", 3/16" 1/4". If you use a specific size pin or rivet, get those size bits, too.
 
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if doing bolsters, recommend getting the # drills that coincide with a slightly smaller hole than the pin stock, then ream to size to ensure a tight fit. (I think it's #40 for 3/32 and #31 for 1/8, but I have to check.)
 
1. Use a center punch to make a dimple in the center crosshairs of the center of your future holes. (I use an automatic center punch, First. I feel it's easier to find center.

* Secure your work.
-remove watches, rings, etc. Roll up sleeves above elbows. Those are dangerous catch points

2. Use a center drill to start the hole. It's short and stiff and won't wander.

3. Use lube, oil, or coolant. In a pinch, I use liquid dishsoap. It's not as good, but better than nothing.

4. Gently bring your moving drill bit into the hole. Don't dwell while drilling. Smooth steady action, Gently bring it up out of the hole. Clear metal chips with a brush. Don't use fingers.

5. As you are about to break through the hole, lighten up on the pressure you are pushing. You will gently Feel it happening. I don't use arm strength so much as the body dynamics, I actlualy use my shoulders and core, More slowly, feeling the whole movement. This way it helps from breaking through to fast, too abrupt.

Machining is a Zen experience.
Lots of using your senses.
Hearing, smells, feel (vibrations, heat, surface finish, etc)

It gets into your Soul

Let the tool do the work, don't force anything.
 
bladegrinder said:
You want to use slow speeds going thru steel too.
Click to expand...
Well, that kinda depends on the steel/metal you are drilling though.

There are a couple of references for drill chuck rpm and the numbers vary slightly, but are all close enough tat I'm not going to say which reference is better. In our shop/makerspace we keep it simple and teach folks that for mild or annealed steel, 240/(drill bit dia) is what to use, and IIRC the equation for hardened/stainless steel is 160/(drill bit dia). For aluminum, 800/dia.
Do some research on what exact materials and tools you are dealing with and use the proper parameters. and you're more likely to achieve success.

EDIT (putting on instructor hat now...) - Also, you have to make sure your feed is adequate, enough to actually cut and drill but not too much to break the bit (harder to do with smaller bits). One thing I say to novice metalworkers in our makerspace is: If the bit is touching the workpiece, but not making any chips, what are you doing? Answer: just generating heat, which will eventually ruin the temper of your bit. So, if the bit is just spinning, the first thing to try is pushing down harder on the chuck.

Also, the use of motor oil (or any non-specific cutting oil for that matter) is questionably better than nothing at all. The main point for adding fluid is to keep the bit cool, not to lubricate it, we want the bit to cut into the metal, not slide along the metal (there is some lubrication on the bit to help clear the chips and spirals, but this isn't the main job of the coolant). Burning motor oil is toxic to breathe, and so not the best choice when it smokes as the bit heats up, (most commercial coolants are water based). The only real problem with water is rusting of your tools if you don't clean up afterwards.
If you want to avoid the toxicity and mess but keep your bits cool, just get used to 'peck' drilling, letting the bit cool in the air after every few seconds of drilling. Or get the proper tools for the job and get some commercial coolant. My favorite is boelube, a waxy like block, developed specifically for drilling holes by boeing back when they actually cared about quality and improving their processes.

I encourage any full-time machinists to correct any errors made above and apologize for any misdirection,
 
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We are probably all assuming, but OP says "brand new drill", not "drill press"...
 
yeah...why I asked what kind of drill...I know several makers that use a handheld drill. BUT, the battery powered wally world units won't cut it. They use contractor grade Makita's or dewalt hi torque drills/drivers.
 
bladegrinder said:
You want to use slow speeds going thru steel too.
Click to expand...

No, not necessarily so, like weo weo nicely wrote up.

I'll add, some steels like stainless, you want slower rpm's but Higher feed rate. (You push harder) Like mentioned, dwelling....not making chips is just creating heat. And will work harden your stainless. Which is Bad
 
Everyone who works in a manufacturing shop should own a copy of The Machinery's Handbook. Tons of information in that book.

To the OP it sounds like you're burning up the drill. A lot of good advice has been given but we will need more information to give any specific remedies.
 
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