What did I buy?

[Piecat]

I picked up these items from my local “Restore” branch in Nanaimo, Canada, for CD$ 15.

Being ignorant of what exactly they are, I turn to the forum members. Some of them look like reamers with a stepped point, whereas the others are obviously drills.

They all are in very good shape, whrere only a couple need touching up. I am confounded by the chucking ends - how can I use them in a home workshop.

The “reamers” consist of the following sizes : 5/32” (1), 3/16” (7), 7/32 (1) and 1/4” (4).

The “drills” consist of the following sizes : 5/32” (1), 3/16” (1), 5/64 (1), 7/64 (3), and !/4 (1).

Can I have some enlightenment, please?

Piecat.

 

[steamer]

Well clearly they're drills! :....as far as the shank is concerned, I've not seen a shank like that before.

The odd one is a step drill....

Dave

 

[blighty]

they could be some sort of "quick release" system.

a builder mate of mine has a hand drill with the same sort of look. on the chuck there is an outer collar that you pull back. you then put the drill in the chuck, let go of the collar, twist the drill bit a bit until you hear a click. then your ready to go.

 

[Springbok]

Well certainly the last pic are drills that will allow you to countersink to a flat, so the your cheese head or allen bolt will not sit proud of the surface. The initial part of the process is the hole you have drilled then use the countersink to the depth you require. In the UK these drills are expensive.
Would suspect the other long drills were for an early collet system poss with a bolt for additional fixing. You can see wear on one where it has not been fixed properly.
Anyway a nice find for the price. The countersink ones are especially usefull.


Bob

 

[lugnut]

I see this type of drill bit around here a lot, mostly in second hand shops. I was told they came from one of the aircraft plants near Seattle, probably Boeing. I usually can buy them for less than 50¢ each. They are a very good quality bit.

 

[user 284]

Yeah there known as aircraft drills. I don't know quite how that quick change system works, But I think drills like that are mostly used in pneumatic drills.

Pete

 

[Stan]

Aircraft drills sold by the pound at the Boeing surplus store and other aircraft manufacturer surplus They can be used in any electric or pneumatic drill. You don't need the quick change chuck. Almost all the drills of that type are are number sizes for rivets (such as #30 - .128" for 1/8" - .125" rivet)

Boeing tools were reground an infinite number of times until the end of a production run, at which time, all were sold as surplus and the next production run (different model plane) got all new tooling. When the tools were sold, some were still new while others had been reduced to a fraction of their original length. Tools like reamers and end mills are marked to four decimal places of reground size.

 

[n4zou]

Yeah there known as aircraft drills. I don't know quite how that quick change system works, But I think drills like that are mostly used in pneumatic drills.

Pete

Ding! Ding! Ding! Winner!

The quick change socket the drills plug into has multiple locking pins that engage the drill shank. Run out on those shanks is less than .0005.

 

[user 284]

LOL, Well I kind of cheated since I own some. I bought a bag of them at the Vancouver hot rod show years ago for 10 bucks. No doubt each drill was at least that price when they were new.

Pete

 

[Springbok]

Well it sound like everyone in America is lucky to have such a amazing throw it away society and then maybe not.
Pete I hope you found the answer to your question
Bob

 

[Piecat]

Thank you to everyone who responded to my question. I've learned some things along the way.

One small puzzle still remains:-

Refer to picture #4 - the items in that group (stepped points) all have their flutes configured for cutting in both forward and reverse direction. I have never seen it on normal drills?

Piecat (Pierre)

 

[Lew Hartswick]

Refer to picture #4 - the items in that group (stepped points) all have their flutes configured for cutting in both forward and reverse direction. I have never seen it on normal drills?

Piecat (Pierre)

They look like conventional flutes to me. For a step drill
...lew...

 

[Charles Lamont]

Refer to picture #4 - the items in that group (stepped points) all have their flutes configured for cutting in both forward and reverse direction. I have never seen it on normal drills?

Well, now you point it out, I see a double land, each side of the spiral, which is unusual I agree. The drills are fairly fast spiral for plenty of rake, for softer materials, so I don't think it is meant to cut in reverse as the rake would be a lot negative. Perhaps it is something to do with chip clearance, lubrication, drilling true or ... ?

 

[chipenter]

Standard step drill for soft material , helps swarf clearing , the same sort of drills are used on armour plate on tanks and warships as it is very sticky.

 

[Blogwitch]

Here in the UK those type of 'stepped' drills are called 'bullet' or sheet metal points, and are used for drilling sheet metal.

The way they work is that the small drill point goes through first, leaving a sharp swarf edge on both sides, then the mill part comes into it's own and basically reamers and cuts it's way through, using the small drill part as a guide, removing off any metal burrs left on both sides from drilling, so leaving a nice clean face all over.

So that sort of confirms it, being from an aircraft company, who will be drilling thousands upon thousands of rivet or bolt holes in soft aluminium skins, and using that type of drill, saves them having to deburr all the holes on either side of the skin, just etch prime and/or joint up with sealant, then rivet or bolt up the skin to the airframe.

A great time saving tool.

John

 

[C.BRAXMAIER]

they could be some sort of "quick release" system.

a builder mate of mine has a hand drill with the same sort of look. on the chuck there is an outer collar that you pull back. you then put the drill in the chuck, let go of the collar, twist the drill bit a bit until you hear a click. then your ready to go.

They are the are for a rotory table, once apon a time i ran one, oh ya it sucked....

 

[Foozer]

Used thousands upon thousands of them at Boeing.
Most are double margin piloted QC bits.
Looks like you have a few of what was called QC 90 bits. short shank to fit the quick change of a 90% drive motor.

The double margin bits give nice round holes whereas the single margins have a tendency to give triangle shape holes in thin stock 063 or so.
Usually could get around 30 holes drilled per bit at 6000 rpm in skin quality aluminum before the bits got dull.

A few follow me home before I retired. Have no idea how those bits knew where I lived. Must of been the trail of bread crumbs.

Robert

 

[Foozer]

using the small drill part as a guide, removing off any metal burrs left on both sides from drilling, so leaving a nice clean face all over.

John

Yup, as the majority of the holes in the AC are hand drilled, to keep hole quality up they are drilled in steps. A #30 pilot followed by .218 then .247 as final for that group. After a while you just cheat and go from the 30 straight to the final .247.
.187/.190 .247/250 holes are about the size for the majority of holes in a 777.

When they start to dull the hole tends to volcano out at the exit. When drilling skin laps with a few thousand holes was easier to change bits every 30 or so holes rather than try to open the lap and debur the holes. IIRC a .003 bur was max, we just used a 4x4 gause and if no threads were caught it was deburred.
The power drillers with auto oilers ran at 20k and could do thousands of holes before a bit change was required. Usually used these motors when the laps called for hundreds of close tolerance (non rivet) holes.

Nothing better than having a 6 inch #30 bit singing at 6k and go snap
Robert

 

[Rayanth]

These drills are precisely what we use at Boeing. They are quick change drill bits for pistol griphand held drill motors.. The one with the shorter chuck shank (pips close to end) are used inan adapter for threaded 90 degree handheld drills. The tips of your drills are what we call double margin, designed to follow the pilot hole of a previously drilled smaller size. I go through a hundred of these things a day =)

I may be able to get more detailed info for you, regarding manufacturers of our drill motors etc, but you should be able to use those in a standard three prong chuck just fine. Note, do NOT put a high chip load on these drills, the welds will break easily.

Ryan.