Quality Control - Stainless?

[btrayfors]

AWAB makes high quality all s/s hose clamps. West Marine/Boat U.S. stores sell them (at outrageous prices). You can find 'em cheaper elsewhere.

Lots of info on line. Google "Awab hose clamps".

They make the screw type also....never had one loosen or corrode or break. Good stuff; worth the extra bucks.

Whoever said s/s can't be tested with a magnet is wrong: good s/s clamps are not ferro-magnetic, just like your rigging.

Bill

[GordMay]

Absolutely ~ use “Smooth” Hose Clamps.

AWAB 316 STAINLESS STEEL SMOOTH BAND HOSE CLAMPS
Goto: ABA of America, Inc. - Manufacturers of high performance hose clamps and quick connectors

And: AWAB LLC

[Pblais]

Here is a source of clamps you can actually buy them from. They are not always the cheapest but they have the largest selection and the do Internet sales and ship quickly.

McMaster-Carr

The store is set up like a catalog with a good search tool. Go to Page 239.

It has non perforated SS 336 clamps and Titanium plus on the prior and next pages some other types some more suitable for engine hoses.

There is even a set of Nylon clamps but it's hard to tell how much clamping power they have. They do tell you the proper torque on most of them. For a basic 1 inch hose (22 - 33mm) they say the torque for SS 316 is 44 pounds but for Titatium is only 40. Sorry no metric conversion on the torque but they do have metric converstion for the sizes.

Things that are nice are smooth or rolled edges to prevent cutting. You'll see when you get into the good clamps they don't sell them by the package but one at a time.

[Weyalan]

All stainless steels are equal, but some are more equal than others! There are standard "recipes" for making any given stainless steel (302, 316, etc). Each recipe has certain tolerances for the amount of each ingredient.
For example, the recipe for 316 stainless is:
16-18% Cr
10-14% Ni
0.25% C
2.0 Mn
1.5-3.0 Si
0.045 P
0.030 S
Balance Fe
The variations can make a difference to both the material's rust resistance and to its "megneticness". Just because a piece of steel is magnetic, it doesn't mean it is not stainless. Also, just because a piece of steel displays rust, doesn't mean it isn't stainless. I have, through my job, worked with various stainless steels, sourced from various parts of the world. 316 sourced from West Germany is a different beast from 316 sourced from Korea.

Having waffled on iterminably, I will just say this: Hose clamps, rusty or not, should be inspected regularly and should be changed periodically regardless of their perceived condition.

[GordMay]

Magnetic Properties of Stainless Steel(s):

Stainless steels can be divided into four (or more) basic groups based on their crystalline structure, and the elements added to the alloy: Austenitic, Ferritic, Martensitic, and Duplex.

All austenitic grades of S/S have very low magnetic permeabilities*, until cold worked. After substantial cold working Grade 304 may exhibit quite strong response to a magnet, whereas Grades 310 and 316 will in most instances still be almost totally non-responsive. Any austenitic (300 series) stainless steel, which has developed magnetic response due to cold work, can be returned to a non-magnetic condition by stress relieving.
There are two subclasses of austenitic stainless steels: chromium-nickel and chromium-manganese-low nickel steels.

* Permeability is the property used to measure how well a material concentrates magnetic fields.

Ferritic stainless steels are magnetic steels that contain chromium (& carbon), but not nickel.

Martensitic grades are magnetic and contain chromium but usually not nickel.

Fittings and hardware are often made of Type 316 stainless to resist corrosion. They are usually highly polished.
Nuts bolts, screws, and other fasteners, and items where strength and wear are required, are usually made of Type 304.

See also:

Stainless Steels – Introduction To Grades, Properties and Applications
Stainless Steels - Introduction To Grades, Properties and Applications, Supplier Data by Aalco

Magnetic Properties of Stainless Steel
http://www.bssa.org.uk/publications/...Properties.pdf

[s/v 'Faith']

Originally Posted by colemj

The 304/316 grades of stainless most used for clamps (or at least desired) are not ferromagnetic like mild steel and will not be attracted to a magnet. .....Some grades of stainless are ferromagnetic (401?), but these are not typically found in common parts like hose clamps and fasteners. 304/316 stainless can become ferromagnetic if it has been worked hard or been mistreated in a certain way, so if the magnet does stick to your rigging, you should probably consider immediate action.....

Mark

I stand corrected. I am not sure how I missed this. Thanks for the info.