Views: 6 Author: Site Editor Publish Time: 2024-11-01 Origin: Site
On August 28, our company received an inquiry for bolts and nuts from an American customer. This was the first inquiry from this customer this year. We send quotations, material test certificate and delivery dates to customers. After this quotation, the customer asked three more questions about bolt products and kept in touch with us.
In October, two months after the first quotation, the customer sent us a purchase order.
Heavy hex bolts and nuts are fasteners used in construction, automotive, and industrial applications. They are thicker and larger than standard hex bolts and nuts, and are designed to be used together.
No | Description of Goods | Quantity | Units |
1 | M8 HEAVY HEX NUT | 30 | EA |
2 | M6 HEAVY HEX NUT | 80 | EA |
3 | M6 x 25 LG HEAVY HEX BOLT | 80 | EA |
4 | M8 x 25 LG HEAVY HEX BOLT | 30 | EA |
Heavy Hex Nut Specification
ASTM A563M heavy hex nut is a mechanical part with a hexagonal shape and a threaded hole inside. It mainly consists of a nut body and a threaded part. The nut body is a hexagonal block structure with six parallel faces and equal sides. This hexagonal structure makes it easy to use a wrench to operate the nut when tightening and loosening.
Chemical Resistance Guide of nuts ASTM A563
TABLE1 Chemical Requirements | ||||||||
Nut Grade | A,B,C,8S | C3,8S3 | D | DH,10S | DH3,10S3 | |||
Heat Analysis | Composition | Composition | Composition | Based on | Composition % | Composiion% | Based on | |
Carbon | 0.55 max | 0.33-0.40 | 0.38-0.48 | 0.30-0.53 | 0.55 max | 0.20-0.55 | 0.20-0.53 | 0.30-0.53 |
Manganese | B | 0.90-1.20 | 0.70-0.90 | 0.60 min | 0.30 min | 0.60 min | 0.40min | 0.60 min |
Phosphorus,max | 0.12 | 0.035 | 0.035 | 0.035 | 0.04 | 0.04 | 0.035 | 0.035 |
Sulfur,max | 0.15D | 0.040 | 0.040 | 0.040 | 0.05E | 0.05E | 0.040 | 0.040 |
Siicon | B | 0.15-0.35 | 0.30-0.50 | B | B | B | B | B |
Copper | B | 0.25-0.45 | 0.20-0.40 | 0.20-0.60 | B | B | 0.20 min | 0.20-0.60 |
Nickel | B | 0.25-0.45 | 0.50-0.80 | 0.20Fmin | B | B | 0.20Fmin | 0.20Fmin |
Chromium | B | 0.45-0.65 | 0.50-0.75 | 0.45 min | B | B | 0.45 min | 0.45 min |
Vanadium | B | B | B | B | B | B | B | B |
Molybdenum | B | B | 0.06 max | 0.10Fmin | B | B | 0.15F min | 0.10Fmin |
Titanium | B | B | B | B | B | B | B | B |
A Based on heat analysis. See 5.3 for product analysis requirements
B Not specified.
C See 5.2.
D For Grades A, B, and 8S a sulfur content of 0,23 96 max is acceptable with the purchasers approval.
E For Grades D, DH, and 10S a sulfur content of 0.05 - 0.15 % is acceptable provided the manganese is 1.35 % min.
F Either Nickel or Molybdenum must be present in the amount specified.
Heavy Hex Bolts Specification
ASTM A325 Type 1 is a standard material specification for high strength carbon steel fasteners, for use in high tensile structural bolting and other general purpose applications. Type 1 is a quenched and tempered carbon steel, alloy steel or boron steel bolting material with minimum tensile requirement of 105 ksi, yield 81 ksi and maximum hardness requirement of 34 HRC, This specification is used for manufacturing heavy profile bolts, screws, stud bolts, threaded rods, anchor bolts and other externally threaded fasteners.
A325 Type 1 Chemical Properties
Chemical Requirements for Type 1 Bolts | ||
Element | Carbon Steel | |
Heat | Product | |
Carbon | 0.30-0.52 | 0.28-0.55 |
Phosphorus,max | 0.040 | 0.048 |
Sulfur,max | 0.050 | 0.058 |
Silicon | 0.15-0.30 | 0.13-0.32 |
Carbon Boron Steel | ||
Element | Heat | Product |
Analysis | Analysis | |
Carbon | 0.30-0.52 | 0.28-0.55 |
Manganese,min | 0.60 | 0.57 |
Phosphorus,max | 0.040 | 0.048 |
Sulfur,max | 0.050 | 0.058 |
Silicon | 0.10-0.30 | 0.08-0.32 |
Boron | 0.0005-0.003 | 0.0005-0.003 |
Element | Alloy Steel | |
Heat | Product | |
Carbon | 0.30-0.52 | 0.28-0.55 |
Manganese,min | 0.60 | 0.57 |
Phosphorus,max | 0.035 | 0.040 |
Sulfur,max | 0.040 | 0.045 |
Silicon | 0.15-0.35 | 0.13-0.37 |
Alloying Elements | A | A |
Alloy Boron Steel | ||
Heat | Product | |
Analysis | Analysis | |
Carbon | 0.30-0.52 | 0.28-0.55 |
Manganese,min | 0.60 | 0.57 |
Phosphorus,max | 0.035 | 0.040 |
Sulfur,max | 0.040 | 0.045 |
Silicon | 0.15-0.35 | 0.13-0.37 |
Boron | 0.0005-0.003 | 0.0005-0.003 |
Alloying Elements | A | A |
How to Inspect Bolts and Nuts?
Appearance inspection
Surface defects: Check whether there are cracks, sand holes, pits, scratches, burrs and other defects on the surface of bolts and nuts.
Rust condition: Check whether there are signs of rust and corrosion. In a humid or corrosive environment, bolts and nuts are prone to rust, and rust will weaken their mechanical properties and shorten their service life.
Thread quality: Observe whether the thread is complete and clear, and whether there are problems such as random buckles and missing teeth. The quality of the thread directly affects the matching accuracy and connection reliability of bolts and nuts.
Dimension inspection
Bolt: Mainly measure the diameter, length, thread length, head size, etc. of the bolt. The accuracy of these dimensions will affect the matching of the bolt and nut and the installation with the connected parts.
Nut: Measure the inner diameter, outer diameter, etc. of the nut. The matching accuracy of the inner diameter of the nut and the outer diameter of the bolt is crucial. If the matching clearance is too large, the connection will be loose; if the matching clearance is too small, it will be difficult to install.
Features of Heavy Hex Nut and Bolts
Heavy Hex Bolts
Have thicker heads than standard hex bolts
Can be made from low and medium carbon steel, alloy, or stainless steel
Can be plain, galvanized, phosphate, zinc, or cadmium plated
Can be threaded all the way up the shaft or have a smooth shoulder area
Are used in construction, repairs, and automotive applications
Heavy Hex Nuts
Are larger and thicker than standard hex nuts
Are typically made from high-grade steel
Are used in construction and heavy-duty industrial applications
Are commonly found in bridge building, tower construction, and other heavy-duty applications
Have a higher proof load strength compared to a standard hex nut
