We are a professional manufacturer of DIN 933 AISI 316L, ASTM A193 GRADE B8M HEX BOLT in China
- Heavy hex bolts have heads that are wider across flats and higher than standard hex bolts.
- ASTM A193 are high strength bolts for high temperature, high pressure or other special applications.
- Stainless steel significantly improves resistance to tarnishing or corrosion.
DIN 933 is a German STANDARD FOR HEX BOLT, which has been preplaced by ISO 4017, however in some places DIN 933 is still used and the dimensions described below in DIN 933 are similar to ISO 4017.
We can supply steel grade 8.8, 10.9, SS316, A2-70, A2-80, A4-70, A4-80 & size from M16 to M64.as well as A193 B8 Hex bolt,A193 B8M hex bolt
DIN 933 hex screws have a fully threaded shank and are manufactured to very strict tolerances.
DIN 933
DIN 933 (ISO4017) Hexagonal bolts can be divided into full-threaded hexagonal bolts , DIN 933 hexagon bolts are often used in conjunction with hex nuts. the tow parts are connected into a whole by threaded connection, which is a detachable connection. the self-locking performance of the fine thread hexagonal bolt is better, and it is mostly used for parts subject to greater impact, vibration or alternating load, can also be used for fine adjustment mechanism.
- Material: Carbon Steel/Stainless steel/duplex stainless steel
- Type: Hex Head, Full thread
- Thread Size: M6 ~ M56
- Surface Finish: Plain, Black, Zinc Plated, Yellow Plated, H.D.G,PTFE coating
- Class: 4.8, 8.8, 10.9, 12.9 SS316, A2-70, A2-80, A4-70, A4-80
- The DIN933 standard is applicable to full-threaded hexagonal bolts with thread diameters of M6-M56, product grades A and B. Class A: d≤24mm and l≤10d or l≤150mm (according to the smaller value). Grade B: d>24 mm or l>10d or 1>150 mm. (Press the smaller value). Different product grades have different values for the corresponding opposite side s, diagonal e, thickness k and length tolerance.
- The general thread diameter specification is M6-M56, and the general carbon steel performance grade is mainly 8.8 and 10.9. When d≤39mm, refer to ISO898-1.
- Surface treatment and thread tolerance: DIN933 hexagon bolts are generally metric (coarse) and fine pitch, with mm millimeters as the unit of measurement. DIN933 coarse thread tolerance is: 6g, the coating is mainly boiled black, electroplating (blue and white zinc, yellow color zinc), non-electrolytic zinc powder coating (GEO). The tolerance matching before coating is mainly 6g/6H, and the tolerance zone matching after galvanizing can be changed to 6h/6G. However, after coating, it is affected by the thickness of the surface coating. When the thread is inspected by the corresponding tolerance, it is also There may be situations where it cannot be matched, and only nuts with matching specifications can be tested.
- Regarding the mechanical performance test: general appearance test and pass-and-limit test are common and necessary tests, and the following test items are carried out according to the actual situation
- → Tensile test: When the specific specifications and length meet the conditions, high-strength carbon steel (8.8, 10.9, 12.9) and stainless steel bolts (70, 80 strength) can be subjected to relevant tensile testing. Carbon steel: 8.8 grade not less than 800MPa/830MPa (greater than m16); 10.9 grade not less than 1000MPa; 12.9 grade not less than 1200MPa.
- →Impact test: Carbon steel products can be subjected to impact test when the specifications meet certain conditions.
- →Hardness test: Carbon steel products can be tested for surface hardness and core hardness.
- →Torsion test: For small-size products, the tensile test cannot be performed, but the torsion test can be performed.
- →Wedge load: high-strength carbon steel products can be tested for selective wedge load.
ASTM A193 B8M CHEMICAL COMPOSTION
The specification for ASTM A193 covers alloy and stainless steel bolting for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. The ASTM A193 specification covers bars, bolts, screws, studs, stud bolts, and wire.
| Grade | Size | Tensile ksi, min | Yield, ksi, min | Elong, %, min | RA % min |
|---|---|---|---|---|---|
| B7 | Up to 2-1/2 | 125 | 105 | 16 | 50 |
| 2-5/8 – 4 | 115 | 95 | 16 | 50 | |
| 4-1/8 – 7 | 100 | 75 | 18 | 50 | |
| B8 Class 1 | All | 75 | 30 | 30 | 50 |
| B8M Class 1 | All | 75 | 30 | 30 | 50 |
| B8 Class 2 | Up to 3/4 | 125 | 100 | 12 | 35 |
| 7/8 – 1 | 115 | 80 | 15 | 35 | |
| 1-1/8 – 1-1/4 | 105 | 65 | 20 | 35 | |
| 1-3/8 – 1-1/2 | 100 | 50 | 28 | 45 | |
| B8M Class 2 | Up to 3/4 | 110 | 95 | 15 | 45 |
| 7/8 – 1 | 100 | 80 | 20 | 45 | |
| 1-1/8 – 1-1/4 | 95 | 65 | 25 | 45 | |
| 1-3/8 – 1-1/2 | 90 | 50 | 30 | 45 | |
| B16 | Up to 2-1/2 | 125 | 105 | 18 | 50 |
| 2-5/8 – 4 | 110 | 95 | 17 | 45 | |
| 4-1/8 – 7 | 100 | 85 | 16 | 45 |
Material Chemical Composition
A193 B8M Hex bolts Chemical composition
| Element | B7 (AISI 4140) | B8 (AISI 304) | B8M (AISI 316) |
|---|---|---|---|
| Carbon | 0.38 – 0.48% | 0.08% max | 0.08% max |
| Manganese | 0.75 – 1.00% | 2.00% max | 2.00% max |
| Phosphorus, max | 0.035% | 0.045% | 0.045% |
| Sulfur, max | 0.040% | 0.030% | 0.030% |
| Silicon | 0.15 – 0.35% | 1.00% max | 1.00% max |
| Chromium | 0.80 – 1.10% | 18.0 – 20.0% | 16.0 – 18.0% |
| Nickel | 8.0 – 11.0% | 10.0 – 14.0% | |
| Molybdenum | 0.15 – 0.25% | 2.00 – 3.00% |
Recommended Nuts,Bolts & Washer
| Bolt Grade | Nuts | Washers |
|---|---|---|
| B7 | A194 Grade 2H | F436 |
| B8 Class 1 | A194 Grade 8 | SS304 |
| B8M Class 1 | A194 Grade 8M | SS316 |
| B8 Class 2 | A194 Grade 8 | SS304 |
| B8M Class 2 | A194 Grade 8M | SS316 |