1/8 inch drive bits

[Jamie]

I was at Sear's the other day doing some hardware shopping when I come
across a cheap "General Tool" micro power driver. For $20 bucks I
thought it to be a good toy to play with.

I then made a stop over at Walmarts and happen to be in the Tool
section and saw a small sized bit set with a lot of different styles
etc. So I got that.

It wasn't until later, I notice these small driver bits which are
3/16 from Walmart, didn't fit the micro power screw driver I
got from Sears. After a little more reading on the package I noticed
they were 1/8 drivers, not 3/16 as I had thought at first glance in the
Sear's store..

All is not lost however. I had the machinist at work bring down the
size of the extension option in the 3/16 set to the 1/8 size and I
can now use the 3/16 bits in the 1/8 micro power screw driver.

I wasn't aware of 1/8 driver bits? Are these a standard or some
fly by night product ? I don't seem to find tomany hits on the web
concerning this.

Jamie

 

[SoothSayer]

I was at Sear's the other day doing some hardware shopping when I come
across a cheap "General Tool" micro power driver. For $20 bucks I
thought it to be a good toy to play with.

I then made a stop over at Walmarts and happen to be in the Tool
section and saw a small sized bit set with a lot of different styles
etc. So I got that.

It wasn't until later, I notice these small driver bits which are
3/16 from Walmart, didn't fit the micro power screw driver I
got from Sears. After a little more reading on the package I noticed
they were 1/8 drivers, not 3/16 as I had thought at first glance in the
Sear's store..

All is not lost however. I had the machinist at work bring down the
size of the extension option in the 3/16 set to the 1/8 size and I
can now use the 3/16 bits in the 1/8 micro power screw driver.

I wasn't aware of 1/8 driver bits? Are these a standard or some
fly by night product ? I don't seem to find tomany hits on the web
concerning this.

Jamie

Micro assembly in china and Taiwan is how it got here. Worked its way
over here. I bought a driver at Harbor Freight 2 years ago this way.

All the bits are for fine assembly work, and some of the "phillips"
drivers do not match any of the numeric sizing standards, so all those
screws in all those Japanese cameras are where you find the sizes for
that, and they started it too.

 

[Fred Abse]

SoothSayer wrote:
"Different" here may mean METRIC sizes..

Are the "Phillips" drivers actually Phillips, or Pozidriv/Supadriv?

Phillips are uncommon outside the USA. Europe and the Far East mainly use
Pozidriv.

The profiles are very different, included angle,etc. As a rule of thumb,
you can get away with a Pozidriv driver in a Phillips screw, but a
Phillips driver will easily "cam out" of a Pozidriv screw, probably
damaging it.

You really need both.

 

[Don Y]

Hi fred,

Are the "Phillips" drivers actually Phillips, or Pozidriv/Supadriv?

Phillips are uncommon outside the USA.

Really? That's worth knowing (I'd never noticed that)

Europe and the Far East mainly use
Pozidriv.

The profiles are very different, included angle,etc. As a rule of thumb,
you can get away with a Pozidriv driver in a Phillips screw, but a
Phillips driver will easily "cam out" of a Pozidriv screw, probably
damaging it.

The Philips is actually *designed* with that feature in mind!
You can predict, for a given applied torque and thrust force,
whether or not the driver will cam out (or the fastener
head sheer off).

E.g., Reed & Prince fasteners (and drivers) will allow you to
exert more torque before the driver disengages from the
screw (usually catastrophically :> ).

As a bit of trivia, a typical adult male can sheer the tip
off a (well made) #0 and #1 Phililps (assuming you can keep
the tip engaged in the fastener at those torque levels and
not mangle the fastener itself!). Some can possibly do this
for a #2, as well! (I believe you have to be Simian to tackle
a #3! :> )

 

[Jamie]

On Sunday, May 13, 2012 3:09:06 PM UTC-7, Tim Shoppa wrote:

[about small-hex drive for screwdriver bits]

I wasn't aware of either 3/16 or 1/8... but I always thought the
metric standard hex bit is 4mm hex

5mm = 0.19685"
3/16" = 0.1875"
4mm = 0.15748"

So, 5mm is close enough to be mistaken for 3/16"; a 3/16" driver will
be over the nominal size, often enough to handle a 5mm item.

My bits in a set (Task Force, from Lowe's I think) are 0.157 or less (0.1556 minimum)
My bits in a Victorinox product (Swiss army knife style) are a known nominal 4mm.

Tim.

if you want a closer look at it..
http://www.amazon.com/General-Tools-500-Precision-Screwdriver/dp/B002XZLTQO

I guess I could look for metric driver bits.

I think that would fall into a 3mm driver shank.


Jamie

 

[SoothSayer]

Phillips are uncommon outside the USA.

Except We invented it, and THEN the other "design variants" followed.

Back then folks had time to 'play' with 'style' and the like.

Europe and the Far East mainly use
Pozidriv.

I found a bit of a listing:

http://en.wikipedia.org/wiki/List_of_screw_drives

The profiles are very different, included angle,etc. As a rule of thumb,
you can get away with a Pozidriv driver in a Phillips screw, but a
Phillips driver will easily "cam out" of a Pozidriv screw, probably
damaging it.

You really need both.

For large screws, sure.

But for all these miniature sizes... I doubt they went through the
trouble to stamp a precision pozi-driv head onto them tiny screws.

More likely "Fearson" type.

 

[SoothSayer]

The Philips is actually *designed* with that feature in mind!
You can predict, for a given applied torque and thrust force,
whether or not the driver will cam out (or the fastener
head sheer off).

The whole reason they were designed is so they would cam out.
You got it right on the money!

Assemblers were over-torquing their slotted fasteners in some instances.
The engineers came up with this and voilà!

Oddly, they can actually have MORE torque applied to them now, and some
(many) are designed to get huge torqueing (seat belt tie down screw) as a
part of their goal. I would not trust my seat belt to a hand tightened
slotted screw.

 

[SoothSayer]

I looked around their tool department and was astonished at their tool
offerings.

...Jim Thompson

At the amount of tools or at the lack thereof?

 

[Fred Abse]

But for all these miniature sizes... I doubt they went through the
trouble to stamp a precision pozi-driv head onto them tiny screws.

Why not? It's as easy to make cold heading dies to the right profile as
the wrong one.

It's called standards compliance.

 

[SoothSayer]

Why not? It's as easy to make cold heading dies to the right profile as
the wrong one.

It's called standards compliance.

Yes,but the capture/hold reasons for the design are not needed at those
micro realms. Bigger screws sure.The little screwdrivers I have for tiny
stuff are none for the pozidriv series muster.

 

[Fred Abse]

Yes,but the capture/hold reasons for the design are not needed at those
micro realms.

They certainly are needed for automated assembly.