No. 4 Finish is produced by rolling stainless steel that has been heated prior to rolling (hot-rolling). This is followed by a heat treatment that produces a uniform microstructure (annealing) and ensures that the stainless steel will meet mechanical property requirements. After these processing steps, the surface has a dark non-uniform appearance called “scale”.
Surface chromium has been lost during the previous processing steps, and, without removal of the scale, the stainless steel would not provide the expected level of corrosion resistance. Chemical removal of this scale is called pickling or descaling, and it is the final processing step. A No. 4 finish has rough, dull, and non-uniform appearance. There may be shiny spots were surface imperfections were removed by grinding. It is generally used in industrial applications, such as equipment for elevated temperature service.
ASTM A240/JIS Standard 4304
3.1 MTC is available once order confirmed，all of our products are conformed with JIS G4304 and ASTM A240 standard.
| Thickness | Width | Length | Surface Finish |
|---|---|---|---|
| 15~85 mm | 914, 1219, 1524 mm | 3048, 6069 mm Max.10M | Black |
| 3~8 mm | 20~2000 mm | 3048, 6069 mm Max.10M | No.1 |
| 8 up ~ 60 mm | 30~2000 mm | Max. 6096 mm | No.1 |
| 0.23-3.0mm | 30-1524-2000mm | Max. 10M | 2B/No.4/HL/8K |
| Great Britain BS970 | U.S.A AISI/SAE | Germany W-Nr Din | Italy UNI | Japan JIS | France AFNOR | Spain UNE |
|---|---|---|---|---|---|---|
| 17/4PH | ASTM A564 Grade 630 | 50049 1.4542 | – | – | Z7CNU 17-04 | – |
| 303S31 | 303 | 1.4305 X10CrNiS18-9 | X10CrNiS1809 | SUS303 | Z8CNF 18-09 | F.5308 |
| 304S11 | 304L | 1.4307 1.4306 X10CrNiS18-9 | X3CrNi1811 X2CrNi1811 | SCS19 SUS304L | Z1CN18-12 Z2CN18-10 | F.3503 |
| 304S15 | 304 | 1.4301 X5CrNi1810 | X5CrNi1810 | SUS304 | Z4CN19-10FF Z5CN17-08 | F.3504 |
| 316S31 | 316 | X5CrNiMo17133 | X5CrNiMo1713 X8CrNiMo1713 | SUS316 | Z6CND18-12-03 | – |
| 316S11 | 316L | 1.4404 X2CrNiMo17132 | X2CrNiMo1713 X8CrNiMo1713 | SUS316L | Z2CND17-12 Z2CND18-13 | F.3533 F.3537 |
| 321S31 | 321 | 1.4541 X6CrNiTi18-10 | X6CrNiTi1811 | SUS321 | Z6CNT18-10 | F.3523 |
| 310 | 310 310S | 1.4845 X12CrNi25-21 | X6CrNi2521 | SUH310 SUS310S | Z8CN25-20 Z12CN25-20 | – |
| 416S21 | 416 | 1.4005 X12CrS13 | X12CrS13 | SUS416 | Z11CF13 | F.3411 |
| 420S29 | – | 1.4024 X15Cr13 | – | SUS410J1 | Z13C13 | F.3415 |
| 420S37 | 420 | 1.4021 X20Cr13 | X20Cr13 | SUS420J1 | Z20C13 | F.3402 |
| 420S45 | 420F | 1.4028 1.4034 X30Cr13 | (G)X30Cr13 | SUS420J2 | Z30C13 Z33C13 | F.3403 |
| 410S21 | 410 | 1.4006 1.4000 X12Cr13 | X12Cr13 X109Cr13 | SUS410 | Z10C13 | F.3401 |
| 431S29 | 431 | 1.4057 X20CrNi172 | X16CrNi16 | SUS431 | Z15CN16-02 | F.3427 |
PVC film is one of the most important factor when purchasing stainless steel material. Basically, 3 types of PVC films are typically applied.
PE50/PE80 black and white film
This is the most widely used film, the thickness normally ranges from 50 micron to 80 microns. There will not be any special function except protection.,
Laser Film(Novacel 4228)
Laser cutting is often applied as a downstream processing. Laser film is a film that can undertake high temperature. If clients apply the wrong pvc, after laser cutting, the pvc will be wrinkled and sticky to the surface.
Transparent Film
There are normally 2 types of blue transparent film, one is the for deep drawing, another one is normal protection film.
Stainless Steel sheet/Plates Packing and Loading Solution
Film Attaching
The edge part should be clean and slit, no residues left.
Back side kraft paper
To make sure there is less moisture going into the pallet, water proof kraft paper should be applied.
Standard sheet package
A layer of wooden plate will be put on the top of the pallet. And 3*2 steel strip will be applied.
Block and bundles
Wooden blocks and bundles will apply on the loading of the pallets.
Top locating
If there are too many pallet in one column，the top part also need be strengthened.
Wooden box package
For stainless steel mirror sheet, we can also apply wooden box.
01
Thickness Tolerance
Normally, different mills will apply 3 types tolerance, like 1.0mm, there will be 0.91-0.92mm/0.94-0.96mm/ 0.98-1.01mm. 3 stages to apply for different application.
02
Width Tolerance
Width tolerance mainly depends on the slitting and cutting machine. We use Taiwan and Italy machinery, which can guarantee +/-0.05 to +/-0.1mm
03
Diagonal Tolerance
Diagonal Tolerance is a key factor to show whether the cut is correct or not. The normal tolerance is +/-2mm。
