degrees of screw stainless steel

In yet another visit to the market place to get
bolts I read the text on the M4x10 socket screw
bag and they come in

stainless steel A4, or S/S
electro-galvanized
galvanized
zink plated

Electro-galvanized, is that a method to get it
galvanized or is it indicative of
better protection?

Zink plated I suppose is the worst - is it the
equivalent of applying zink spray after
removing rust from an automobile body?

Also these screws come in small packs - the
smallest only ten pieces a bag! And even the
S/Ss aren't that expensive. So why would anyone
settle for worse? Or are there advantages with
the galvanized and/or zink plated stuff in
certain conditions?

/the hairdresser

--
underground experts united
http://user.it.uu.se/~embe8573

On 6/9/2017 5:27 PM, Emanuel Berg wrote:
In yet another visit to the market place to get
bolts I read the text on the M4x10 socket screw
bag and they come in

stainless steel A4, or S/S
electro-galvanized
galvanized
zink plated

Electro-galvanized, is that a method to get it
galvanized or is it indicative of
better protection?

Zink plated I suppose is the worst - is it the
equivalent of applying zink spray after
removing rust from an automobile body?

Also these screws come in small packs - the
smallest only ten pieces a bag! And even the
S/Ss aren't that expensive. So why would anyone
settle for worse? Or are there advantages with
the galvanized and/or zink plated stuff in
certain conditions?

/the hairdresser

where are you buying these things exactly? (what country?) I don't
recall ever seeing zinc-plated stainless bolts, tho I suppose I haven't
seen everything.

For non-marine uses--stainless tends to gall easily so the purpose of a
coating is usually just to prevent the threads from getting sticky with
repeated insertion/removal.

In the US, normal stainless bolts are mostly 304 and
extra-corrosion-resistant (marine-grade) ones are 316:
https://en.wikipedia.org/wiki/Stainless_steel

Chrome-plated bolts look a bit nicer than the plain-stainless (no
finish), if you wanted silver shiny bolts.

coatings are plain, oxide or chrome.
mcmaster (USA) also shows silver-plated ones, but they're rather
expensive and I've never seen them used for anything IRL.

DougC wrote:

where are you buying these things exactly?
(what country?)

Sweden. The shop is "Clas Ohlson" which also
has shops in Dubai, Finland, Germany, Norway
and the UK. The range varies, I suppose.

The best thing about the shop here is that it
is located in the very city center. All other
shops (Biltema, Bauhaus, etc.) are in the
industrial areas. It is very close by car and
even by bike but I still don't like to go
there, it feels half the day is spent doing it,
and a lot of blue-collar people do it
*every day*, sometimes I think as an excuse not
to do actual work.

I don't recall ever seeing zinc-plated
stainless bolts

It just says zinc plated if that matters.
The galvanized doesn't say stainless either,
just either galvanized or electro-galvanized.
The stainless says "Stainless steel A4" and
"S/S".

--
underground experts united
http://user.it.uu.se/~embe8573

On 6/9/2017 6:02 PM, DougC wrote:
On 6/9/2017 5:27 PM, Emanuel Berg wrote:
In yet another visit to the market place to get
bolts I read the text on the M4x10 socket screw
bag and they come in

stainless steel A4, or S/S
electro-galvanized
galvanized
zink plated

Electro-galvanized, is that a method to get it
galvanized or is it indicative of
better protection?

Zink plated I suppose is the worst - is it the
equivalent of applying zink spray after
removing rust from an automobile body?

Also these screws come in small packs - the
smallest only ten pieces a bag! And even the
S/Ss aren't that expensive. So why would anyone
settle for worse? Or are there advantages with
the galvanized and/or zink plated stuff in
certain conditions?

/the hairdresser

where are you buying these things exactly? (what country?) I
don't recall ever seeing zinc-plated stainless bolts, tho I
suppose I haven't seen everything.

For non-marine uses--stainless tends to gall easily so the
purpose of a coating is usually just to prevent the threads
from getting sticky with repeated insertion/removal.

In the US, normal stainless bolts are mostly 304 and
extra-corrosion-resistant (marine-grade) ones are 316:
https://en.wikipedia.org/wiki/Stainless_steel

Chrome-plated bolts look a bit nicer than the
plain-stainless (no finish), if you wanted silver shiny bolts.

coatings are plain, oxide or chrome.
mcmaster (USA) also shows silver-plated ones, but they're
rather expensive and I've never seen them used for anything
IRL.



Used to see silver plate for electrical connector screws but
I haven't seen one in many years.

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

Silver tarnishes ?

For bicycle use go with grade 5

5 is hard strong steel somewhat rust resistant..

Coat with thinned linseed

Hardware store SS maybe grade 2.5.

Go to the industrial era.

Go to the industrial era.

Ha! Of course, it is unavoidable sometimes.
Some stuff isn't available elsewhere. It is not
so industrial anymore BTW. De-industrialized
rather. But many of the hardware stores are
located there and their profits seem not that
bothered by the decay...

--
underground experts united
http://user.it.uu.se/~embe8573

On 6/9/2017 9:01 PM, wrote:
Silver tarnishes ?

For bicycle use go with grade 5

5 is hard strong steel somewhat rust resistant..

Coat with thinned linseed

Hardware store SS maybe grade 2.5.

Go to the industrial era.

Incorrect... in this instance.

The SAE system is only used in the US, and it is only used for carbon
(non-stainless) bolts and nuts.
http://www.engineeringtoolbox.com/st...es-d_1426.html

Who is SAE
https://en.wikipedia.org/wiki/SAE_International

Stainless bolts usually only have one-half to one-third the tensile
strength of "regular-steel" bolts, by the by. The stainless is tougher
though (it can take repeated flexing better).

~~~

There's a bunch of screw thread standards too. Pick any one you want
https://en.wikipedia.org/wiki/Screw_...andard_threads

The socket screws are

DIN 912 / ISO 4762 Socket Cap Screw A2/A4 Stainless Steel

and the washers are

DIN 125 / ISO 7089, 7090 Flat Washer A2/A4 Stainless

It says they are A4 on the bags.

http://fullerfasteners.com/products/...rew-stainless/
http://fullerfasteners.com/products/...her-stainless/

--
underground experts united
http://user.it.uu.se/~embe8573

Emanuel Berg wrote:

The socket screws are

DIN 912 / ISO 4762 Socket Cap Screw A2/A4Â*Stainless Steel

and the washers are

DIN 125 / ISO 7089, 7090 Flat Washer A2/A4Â*Stainless

I have a German Heyco double ended spanner (10
and 13 mm) which is DIN 895. Wow, what does it
all mean? Some German system of
standardization...

--
underground experts united
http://user.it.uu.se/~embe8573

On 6/9/2017 9:04 PM, Emanuel Berg wrote:
Emanuel Berg wrote:

The socket screws are

DIN 912 / ISO 4762 Socket Cap Screw A2/A4Â Stainless Steel

and the washers are

DIN 125 / ISO 7089, 7090 Flat Washer A2/A4Â Stainless

I have a German Heyco double ended spanner (10
and 13 mm) which is DIN 895. Wow, what does it
all mean? Some German system of
standardization...


I own some specialty Heyco wrenches. Nice quality.
Yes, DIN = German Industrial Standard, which has become more
successful than the French format SI. SI is called Standard
Internationale because no one else uses it.


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