Water Bottle Cage Mount Screws: M4 or M5?

I want to order some, but can't figure out the nomenclature.

They measure just a hair under 5 mm, but take a 4mm Allen key.

So I guess they're either "m4" or "m5"... but which?
--
PeteCresswell

(PeteCresswell) wrote:
I want to order some, but can't figure out the nomenclature.
They measure just a hair under 5 mm, but take a 4mm Allen key.
So I guess they're either "m4" or "m5"... but which?

Machine threads measure at the OD of the thread. Less
clearance (although nominally 5mm), actual is probably 0.485mm.

DIN 985 spec for an m5x0.8 bolt is a 4mm allen drive. Most
screws will be at that standard.

Specific parts, such as the classic Shimano DOXT of the
early 1980s, may have 6mm (or 5mm) allen drive. DIN 7991 for
5mm is a 3mm allen key but Shimano SPD cleat screws use a
4mm key. These are specials, not DIN standard fasteners.

At any rate, although parts makers may choose a different
size allen drive, a special thread is virtually unknown for
fasteners today.

p.s. If you're a 'regular' at your LBS, 5mm screws are often
free for the asking.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

AMuzi wrote:
(PeteCresswell) wrote:
I want to order some, but can't figure out the nomenclature.
They measure just a hair under 5 mm, but take a 4mm Allen key.
So I guess they're either "m4" or "m5"... but which?

Machine threads measure at the OD of the thread. Less clearance
(although nominally 5mm), actual is probably 0.485mm.

DIN 985 spec for an m5x0.8 bolt is a 4mm allen drive. Most screws will
be at that standard.

Specific parts, such as the classic Shimano DOXT of the early 1980s, may
have 6mm (or 5mm) allen drive. DIN 7991 for 5mm is a 3mm allen key but
Shimano SPD cleat screws use a 4mm key. These are specials, not DIN
standard fasteners.

At any rate, although parts makers may choose a different size allen
drive, a special thread is virtually unknown for fasteners today.

p.s. If you're a 'regular' at your LBS, 5mm screws are often free for
the asking.

D'oh!

First sentence should end "4.85mm".
oops

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Per AMuzi:
First sentence should end "4.85mm".

I'm glad to hear that bc when I measured them with my new
caliper, that's what I got - instead of 5mm - and I was starting
to wonder about the device's accuracy....
--
PeteCresswell

Per AMuzi:
First sentence should end "4.85mm".

(PeteCresswell) wrote:
I'm glad to hear that bc when I measured them with my new
caliper, that's what I got - instead of 5mm - and I was starting
to wonder about the device's accuracy....

If both a nut and screw were truly 5mm, you could not turn them.

Here's a typical thread guide:
http://mdmetric.com/tech/threadtech.pdf

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

Per AMuzi:
First sentence should end "4.85mm".

"(PeteCresswell)" wrote
I'm glad to hear that bc when I measured them with my new
caliper, that's what I got - instead of 5mm - and I was starting
to wonder about the device's accuracy....

Phil W Lee wrote:
The size of the standard metric threads is the size of the bar stock
you need if you are going to cut that size thread in it.
Of course, that will be different from the size you need if you roll a
thread onto a bar
I'm not sure if you can still get them (mine is getting on a bit), but
the Zeus book used to be the standard reference.
Ah, a quick google reveals this:
http://www.axminster.co.uk/product.a...33&src=froogle
At that price, it's silly not to have one if you ever need to be
concerned with thread fitment or any kind of engineering or fitting
jobs.
It's laminated, so will last almost forever, even in a workshop.

Or
http://www.alibris.com/booksearch?bi....y=0&hs=Submit

http://preview.tinyurl.com/yeye7x8

It only hurts once.
My 22d edition is well worn and was worth every penny. Like
SnapOn, the value far exceeds the price.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

In article ,
says...


(PeteCresswell) wrote:
I want to order some, but can't figure out the nomenclature.
They measure just a hair under 5 mm, but take a 4mm Allen key.
So I guess they're either "m4" or "m5"... but which?

Machine threads measure at the OD of the thread. Less
clearance (although nominally 5mm), actual is probably 0.485mm.

DIN 985 spec for an m5x0.8 bolt is a 4mm allen drive. Most
screws will be at that standard.

Specific parts, such as the classic Shimano DOXT of the
early 1980s, may have 6mm (or 5mm) allen drive. DIN 7991 for
5mm is a 3mm allen key but Shimano SPD cleat screws use a
4mm key. These are specials, not DIN standard fasteners.

At any rate, although parts makers may choose a different
size allen drive, a special thread is virtually unknown for
fasteners today.

p.s. If you're a 'regular' at your LBS, 5mm screws are often
free for the asking.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
Right. If you're a regular at some of the high-end shops around here,
meaning you've paid full retail for one or two bikes, they may
inclinded to give you a bolt. Otherwise .50 - $1 a piece. Going to the
local hardware store nets you the same thing at 5 cents each.

Ronko wrote:
In article ,
says...


(PeteCresswell) wrote:
I want to order some, but can't figure out the nomenclature.
They measure just a hair under 5 mm, but take a 4mm Allen key.
So I guess they're either "m4" or "m5"... but which?

Machine threads measure at the OD of the thread. Less
clearance (although nominally 5mm), actual is probably 0.485mm.

DIN 985 spec for an m5x0.8 bolt is a 4mm allen drive. Most
screws will be at that standard.

Specific parts, such as the classic Shimano DOXT of the
early 1980s, may have 6mm (or 5mm) allen drive. DIN 7991 for
5mm is a 3mm allen key but Shimano SPD cleat screws use a
4mm key. These are specials, not DIN standard fasteners.

At any rate, although parts makers may choose a different
size allen drive, a special thread is virtually unknown for
fasteners today.

p.s. If you're a 'regular' at your LBS, 5mm screws are often
free for the asking.

Right. If you're a regular at some of the high-end shops around here,
meaning you've paid full retail for one or two bikes, they may
inclinded to give you a bolt. Otherwise .50 - $1 a piece.


I'll tire-kick at a half-dozen LBSes multiple time each before
I buy a bike (from only one of them, of course), they need to
amortize all of that time.

LBSers have to eat too.


Going to the
local hardware store nets you the same thing at 5 cents each.


Hardware store guys get their calories from the beer, so they don't
have to eat. :-)

(errr, so do many cyclists, I gather)


--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.liamg\100cm.j.dat/"

On 2/26/2010 10:51 PM Tad McClellan wrote:


Hardware store guys get their calories from the beer, so they don't
have to eat. :-)

(errr, so do many cyclists, I gather)

You've seen me about town, then.

--
Mike "Rocket J Squirrel"
Bend, Oregon

Mike Rocket J Squirrel wrote:
On 2/26/2010 10:51 PM Tad McClellan wrote:


Hardware store guys get their calories from the beer, so they don't
have to eat. :-)

(errr, so do many cyclists, I gather)

You've seen me about town, then.


--
Mike "Rocket J Squirrel"
Bend, Oregon


I've not been to Bend, but I sure enjoy touring the many microbreweries
when I visit Portland!


--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.liamg\100cm.j.dat/"