Surface finish table guide

Surface Finishes Table Guide

Description	BS 1449 Part 2	BS EN 10088-2	RA um (approx.)	Reflectivity % 60 deg (approx)	Glos Units
COARSE GROUND 80 GRIT	3A	2G	2.5	10	N/A
240 GRIT ALUM/OXIDE	3B OR 4	2J	1.0	10	N/A
180 GRIT ALUM/OXIDE	3B OR 4	2J	1.25	10	N/A
240S SILICON CARBIDE	NO.5	2K	0.4	30	N/A
240 IMAGE	NO.5	2K	0.4	30/40	N/A
SATIN BRUSH (Long grain)	3B BRUSH	2K	0.2	35/45	N/A
SATIN BRUSH (Short Grain)	3B BRUSH	2K	0.2	35/45	N/A
BRIGHT POLISH	NO.7	2P	0.05	53/60	580/620
MIRROR	NO.8	2P	0.05	58/63	590/630

B.S 1449 Part 2 & euro Standard. EN10088-2
Please note: Reference to the above standards does not ensure conformity from different suppliers and processors.

Ra um (Roughness Average) or (CLA)
Internationally recognised parameter of Roughness
Units can be: um - microns - millionth of a metre
uinch - microinches - millionth of an inch

1 um is approximately 40 uinch