Hex bolts (six sided heads) are the industry standard for fasteners with forged heads. ASTM A307 grade A bolts, all SAE hex bolts, and several other common specifications require a standard (finished) hex head. For specifications such as A307 grade B, A325 and A490 that require a heavy hex pattern, refer to dimensional tolerances for heavy hex bolts or structural bolts.
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Manufacturing
QBH Bolt manufactures hex bolts from 1/4″ diameter through 3″ diameter in most ASTM, AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head dimensions or bolt heads with your company’s name and/or logo.
High-Strength Grade 8 Steel Hex Head Screws
Made from Grade 8 steel, these screws can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. They are at least 25% stronger than medium-strength steel screws. Grade 8 steel hex head screws are marked with six radial lines. Length is measured from under the head.
Zinc yellow-chromate plated steel screws resist corrosion in wet environments. Zinc-aluminum-coated steel screws are about five times as corrosion resistant as zinc yellow-chromate plated screws and have good resistance to salt water and acids. Also known as ultra coat and armor coat. To maintain corrosion resistance, use these screws with zinc-aluminum-coated nuts and washers.
Match the thread spacing of mating components. Coarse threads are the industry standard; choose these screws if you don’t know the threads per inch. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance.
Screws that meet ASTM A354BD or SAE J429 comply with specifications and testing requirements for material quality. Screws that meet ASME B18.2.1 or ASME B18.6.3 comply with specifications for dimensional standards.
| Product name | HEX BOLTS |
| Standard | ASTM A307A |
| Size | 3/8"-2" |
| Class | Gr.A |
| Finish | Z.P., B.Z.P.,PLAIN, BLACK, H.D.G., dacromet, geomet, nickle plated, mechanical zinc plated,ect. |
| Packing | bulk/boxes in cartons, bulk in poly bags/-buckets, etc |
| Pallet | solid wood pallet, plywood pallet, ton box/bag, etc. |
| Mechanical Properties: | GB/T 3098.1 |
Max body length : 800mm/32in

Screw Thread d | |
| PP | UNC | | UNF | | 8-UN | | ds | max | | min | | s | max | | min | | e | max | | min | | k | max | | min | | r | max | | min | | b | L≤6 | | L>6 | | | 20 | 18 | 16 | 14 | 13 | 11 | 10 | 9 | 8 | 7 | 7 | 6 | | 28 | 24 | 24 | 20 | 20 | 18 | 16 | 14 | 12 | 12 | 12 | 12 | | - | - | - | - | - | - | - | - | - | 8 | 8 | 8 | | 0.26 | 0.324 | 0.388 | 0.452 | 0.515 | 0.642 | 0.768 | 0.895 | 1.022 | 1.149 | 1.277 | 1.404 | | 0.237 | 0.298 | 0.36 | 0.421 | 0.482 | 0.605 | 0.729 | 0.852 | 0.976 | 1.098 | 1.223 | 1.345 | | 0.438 | 0.5 | 0.562 | 0.625 | 0.75 | 0.938 | 1.125 | 1.312 | 1.5 | 1.688 | 1.875 | 2.062 | | 0.425 | 0.484 | 0.544 | 0.603 | 0.725 | 0.906 | 1.088 | 1.269 | 1.45 | 1.631 | 1.812 | 1.994 | | 0.505 | 0.577 | 0.650 | 0.722 | 0.866 | 1.083 | 1.299 | 1.516 | 1.732 | 1.949 | 2.165 | 2.382 | | 0.484 | 0.552 | 0.620 | 0.687 | 0.826 | 1.033 | 1.240 | 1.447 | 1.653 | 1.859 | 2.066 | 2.273 | | 0.188 | 0.235 | 0.268 | 0.316 | 0.364 | 0.444 | 0.524 | 0.604 | 0.7 | 0.78 | 0.876 | 0.94 | | 0.15 | 0.195 | 0.226 | 0.272 | 0.302 | 0.378 | 0.455 | 0.531 | 0.591 | 0.658 | 0.749 | 0.81 | | 0.030 | 0.030 | 0.030 | 0.030 | 0.030 | 0.060 | 0.060 | 0.060 | 0.090 | 0.090 | 0.090 | 0.090 | | 0.010 | 0.010 | 0.010 | 0.010 | 0.010 | 0.020 | 0.020 | 0.020 | 0.030 | 0.030 | 0.030 | 0.030 | | 0.7500 | 0.8750 | 1.0000 | 1.1250 | 1.2500 | 1.5000 | 1.7500 | 2.0000 | 2.2500 | 2.5000 | 2.7500 | 3.0000 | | 1.0000 | 1.1250 | 1.2500 | 1.3750 | 1.5000 | 1.7500 | 2.0000 | 2.2500 | 2.5000 | 2.7500 | 3.0000 | 3.2500 | |
Screw Thread d | |
| PP | UNC | | UNF | | 8-UN | | ds | max | | min | | s | max | | min | | e | max | | min | | k | max | | min | | r | max | | min | | b | L≤6 | | L>6 | | | 6 | - | 5 | - | 4-1/2 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | | 12 | - | - | - | - | - | - | - | - | - | - | - | | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | | 1.531 | 1.658 | 1.785 | 1.912 | 2.039 | 2.559 | 2.827 | 3.081 | 3.335 | 3.589 | 3.858 | 4.111 | | 1.47 | 1.591 | 1.716 | 1.839 | 1.964 | 2.461 | 2.711 | 2.961 | 3.21 | 3.461 | 3.726 | 3.975 | | 2.25 | 2.438 | 2.625 | 2.812 | 3 | 3.75 | 4.125 | 4.5 | 4.875 | 5.25 | 5.625 | 6 | | 2.175 | 2.356 | 2.538 | 2.719 | 2.9 | 3.625 | 3.988 | 4.35 | 4.712 | 5.075 | 5.437 | 5.8 | | 2.598 | 2.815 | 3.031 | 3.248 | 3.464 | 4.330 | 4.763 | 5.196 | 5.629 | 6.062 | 6.495 | 6.928 | | 2.480 | 2.616 | 2.893 | 3.099 | 3.306 | 4.133 | 4.546 | 4.959 | 5.372 | 5.786 | 6.198 | 6.612 | | 1.036 | 1.116 | 1.196 | 1.276 | 1.388 | 1.708 | 1.869 | 2.06 | 2.251 | 2.38 | 2.572 | 2.764 | | 0.902 | 0.978 | 1.054 | 1.13 | 1.175 | 1.479 | 1.632 | 1.815 | 1.936 | 2.057 | 2.241 | 2.424 | | 0.090 | 0.090 | 0.120 | 0.120 | 0.120 | 0.190 | 0.190 | 0.190 | 0.190 | 0.190 | 0.190 | 0.190 | | 0.030 | 0.030 | 0.040 | 0.040 | 0.040 | 0.060 | 0.060 | 0.060 | 0.060 | 0.060 | 0.060 | 0.060 | | 3.2500 | 3.5000 | 3.7500 | 4.0000 | 4.2500 | 5.2500 | 5.7500 | 6.2500 | 6.7500 | 7.2500 | 7.7500 | 8.2500 | | 3.5000 | 3.7500 | 4.0000 | 4.2500 | 4.5000 | 5.5000 | 6.0000 | 6.5000 | 7.0000 | 7.5000 | 8.0000 | 8.5000 | |
Mechanical property :SAEJ429

Process flow
Cold forging
Annealing treatment(if need) ➨ wiredrawing ➨ clod forging ➨ thread rolling ➨make heat treatment(if need) ➨ Finish ➨ Packing
Hot forging
Cutting material ➨ hot forging ➨ turning ➨ shrink diameter(half thread) ➨thread rolling ➨ make heat treatment(if need) ➨ Finish ➨ Packing
Product Grade
Grade2 Grade5 Grade8
Materials and Chemical compstition
1008
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu | Al |
| 0.06 | 0.06 | 0.33 | 0.013 | 0.003 | 0.01 | 0 | 0.01 | 0.028 |
1035
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu |
| 0.34 | 0.13 | 0.73 | 0.012 | 0.002 | 0.02 | 0.01 | 0.02 |
10B21
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | B |
| 0.2 | 0.04 | 0.81 | 0.017 | 0.007 | 0.017 | 0.0021 |
1045
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu |
| 0.45 | 0.23 | 0.58 | 0.014 | 0.006 | 0.057 | 0.008 | 0.016 |
40CR
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu |
| 0.4 | 0.21 | 0.54 | 0.015 | 0.008 | 0.95 | 0.02 | 0.02 |
35CRMO
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu | Mo |
| 0.35 | 0.22 | 0.59 | 0.01 | 0.003 | 0.93 | 0.01 | 0.01 | 0.21 |
42CRMO
| CHEMICAL COMPOSI % |
| C | Si | Mn | P | S | Cr | Ni | Cu | Mo |
| 0.42 | 0.27 | 0.92 | 0.013 | 0.004 | 1.01 | 0.03 | 0.04 | 0.2 |
Our Services
Professional Manufacturer: All of our Fastener are designed and manufactured according to buyers'
specification and performance.
Quality is guaranteed: Durability testing and critical technical design to enhance fasteners lifetime.
Cost effective: Competitive prices with professional factory supply
Perfect fastening solution with 15+ years experiences to solve your problem: Wide range of parts selection.
Customized Ideal Fasteners: customized services according to the samples and drawings offered.
Free Samples for Standard Fastener from Jiaxing City Qunbang Hardware
We Promise:
1.High quality
2. Competitive price
3. The shortest delivery
4. The fastest response
5. The best service
FAQ
1. How do you let me trust you.
Jiaxing City Qunbang Hardware Co.,ltd hs its own right of import and export,QBH trademark in China,United States,European Union have been registered.At the same time,you can also check the registration information of our company in the China industry and Commerce system.
2. How about your price.
We will be based on different markets,for different quality and quantity,tailor-made prices for customers,in order to achieve win-win goal.
3. How do you control your quality.
Incoming quality contral( IQC)→Process Quality control(PQC)→Output quality control(OQC),and the random samples is sent to TUV for testing.If the customer received the goods and found quality problems,QBH company promises to be responsible for returning money or replenishing the goods
4. Could you provide free samples?
For new customer, We can provide free samples for standard fastener, But the clients will pay the express
charges. For old customer, We will send you free samples and pay express charges by ourself.
5. Do you accept small order?
QBH company can accept small orders if we have them in stock.Generally speaking,the stock probability of stainless steel fasteners is higher than that of carbon steel fasteners.
6. How about your delivery time
What we pursure is the high efficiency movement pattern,the stainless steel fastener delivery time about 15days,the carbon steel fastener will it about 30days
7. What is your packing.
Usually 25KG/carbon,36CTNS on the pallets,or 20-30kg/Bags,then on the pallet,QBH company personalized packagingis also available,like 10PCS/plastic bag or 10pcs/box,it can print some information
such as LOGO and pattern of customers.
8. What is your payment term
Normally,our terms of payment are TT and L/C,if we cooperate for a long time,we can reach the point of mutual trust,and fully support our customers to become bigger and stronger in the local market.
Not only in the price concessions,but also in the payment can also be made on credit,Specific credit sales time needs to be negotiated separately.