Grade Carbon
Silicon
Manganese Phosphorous Sulphur
Nickel
Chromium Molybdenum
304
DIN
1.4301
<=0.08
<=1.00
<=2.00
<=0.035
<=0.035 8.00 - 10.50 18.00 - 20.00
-
316
DIN
1.4401
<=0.09
<=1.00
<=2.00
<=0.035
<=0.035 10.00 - 14.00 16.00 - 18.00 2.00 - 3.00
Part 1 - 1991
(Sections 1.1 to 1.15 replaced by EN 1088) - This standard specifies the properties of
various stainless steels, and includes a general reference of six mechanically polished surfaces of
different nominal grit sizes.
Part 2 - 1983
(Amended in 1985 &¢1991 and 683/13 Euronorm 88)
Nominal Grit Size
BS 1449 Pt 2
EN 1088
Description
80 -100
3A
1G/2G
Ground Ra nom 2.5 µm
180
3B
2J
Ground Ra nom 1.25 µm
240
4
1J/2J
Dull Polish Ra nom 0.6 µm
320
5
1K/2K
Satin Polish Ra > 0.5 µm
590 - 630
7
2P
Bright Polish Ra nom 0.05 µm
800
8
1P/2P
Mirror Finish Ra nom 0.05 µm
There are many grades of stainless steel, but the
majority of stainless steel items in this catalogue
are 304 and 316.
Grade 304 is the most common stainless steel,
and satisfies a broad demand for adequate
performance at an affordable price. It has good
corrosion resistance in a wide variety of
environments. It is the best choice for indoor
use (except swimming pools).
Grade 316 has a higher level of corrosion
resistance and is often referred to as marine
grade. Typical applications are architectural
components where they are exposed to extreme
weather conditions and climatic conditions, such
as near the coast, near heavy industrial sites or
in/around swimming pools.
Stainless steel is not maintenance free but
maintenance friendly and when using stainless
steel material outdoors, you need to clean
periodically, especially in aggressive
environments like coastal areas or swimming
pools. The chlorine rich atmosphere driven in
from the sea can affect in-land stainless as far as
20 miles from the coast.
Choosing the correct grade can dramatically
improve the corrosion resistance againstchlorine,
but other things should be taken into
consideration.
Surface finish is a critical element in the battle
against corrosion. The British Stainless Steel
Association (BSSA) recommend that a surface
finish of no less than 0.5µm Ra (320 Grit) is used
on all applications subjected to a chlorine rich
environment. A surface any rougher than this will
retain corrosive particles and rust will inevitably
follow.
STANDARDS RELEVANT TO SURFACE FINISH - BS 1449
54
PRODUCT SELECTION
