Product Details
ASME B 18.3 Hexagon Socket Head Cap Screws Cylindrical Socket Head Cap Screw UNC UNF Gr2 5 8 Black YZP Used In Machine
Specification
Alloy Steel Socket Head Screws
With a tensile strength of 170,000 psi, these alloy steel screws are stronger than Grade 8 steel screws. Length is measured from under the head.
Black-oxide steel screws are mildly corrosion resistant in dry environments. Zinc-plated steel screws resist corrosion in wet environments. Zinc-aluminum-coated steel screws are 40 times as corrosion resistant as zinc-plated screws and comparable to Magni-coated screws. They withstand 1,000 hours of salt spray per ASTM B117.
Coarse threads are the industry standard; choose these screws if you don’t know the pitch or threads per inch. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance. They are not compatible with coarse threads.
Screws that meet ASTM A574, ASTM A574M, and ISO 898-1 comply with specifications and testing requirements for material quality. Screws that meet ASME B18.3, ASME B18.3M, ISO 21269, and ISO 4762 (formerly DIN 912) comply with specifications for dimensional standards.

Size | |
d | Screw Diameter | PP | UNC | UNF | UNEF | ds | max=nominal size | min | dk | max | min | k | max | min | s | Nominal Size | t | min | b | min | | 0.060 | 0.073 | 0.086 | 0.099 | 0.112 | 0.125 | 0.138 | 0.164 | 0.190 | 0.250 | 0.3125 | 0.375 | 0.4375 | 0.500 | 0.625 | 0.750 | - | 64.0 | 56.0 | 48.0 | 40.0 | 40.0 | 32.0 | 32.0 | 24.0 | 20.0 | 18.0 | 16.0 | 14.0 | 13.0 | 11.0 | 10.0 | 80.0 | 72.0 | 64.0 | 56.0 | 48.0 | 44.0 | 40.0 | 36.0 | 32.0 | 28.0 | 24.0 | 24.0 | 20.0 | 20.0 | 18.0 | 16.0 | - | - | - | - | - | - | - | - | - | 32.0 | 32.0 | 32.0 | 28.0 | 28.0 | 24.0 | 20.0 | 0.060 | 0.073 | 0.086 | 0.099 | 0.112 | 0.125 | 0.138 | 0.164 | 0.190 | 0.250 | 0.3125 | 0.375 | 0.4375 | 0.500 | 0.625 | 0.750 | 0.0568 | 0.0695 | 0.0822 | 0.0949 | 0.1075 | 0.1202 | 0.1329 | 0.1585 | 0.1840 | 0.2435 | 0.3053 | 0.3678 | 0.4294 | 0.4919 | 0.6163 | 0.7406 | 0.096 | 0.118 | 0.140 | 0.161 | 0.183 | 0.205 | 0.226 | 0.270 | 0.312 | 0.375 | 0.469 | 0.562 | 0.656 | 0.750 | 0.938 | 1.125 | 0.091 | 0.112 | 0.134 | 0.154 | 0.176 | 0.198 | 0.218 | 0.262 | 0.303 | 0.365 | 0.457 | 0.550 | 0.642 | 0.735 | 0.921 | 1.107 | 0.060 | 0.073 | 0.086 | 0.099 | 0.112 | 0.125 | 0.138 | 0.164 | 0.190 | 0.250 | 0.312 | 0.375 | 0.438 | 0.500 | 0.625 | 0.750 | 0.057 | 0.070 | 0.083 | 0.095 | 0.108 | 0.121 | 0.134 | 0.159 | 0.185 | 0.244 | 0.306 | 0.368 | 0.430 | 0.492 | 0.616 | 0.740 | 0.050 | 0.062 | 0.078 | 0.078 | 0.094 | 0.094 | 0.109 | 0.141 | 0.156 | 0.188 | 0.250 | 0.312 | 0.375 | 0.375 | 0.500 | 0.625 | 0.025 | 0.031 | 0.038 | 0.044 | 0.051 | 0.057 | 0.064 | 0.077 | 0.090 | 0.120 | 0.151 | 0.182 | 0.213 | 0.245 | 0.307 | 0.370 | 0.50 | 0.62 | 0.62 | 0.62 | 0.75 | 0.75 | 0.75 | 0.88 | 0.88 | 1.00 | 1.12 | 1.25 | 1.38 | 1.50 | 1.75 | 2.00 | |
Size | |
d | Screw Diameter | PP | UNC | UNF | UNEF | ds | max=nominal size | min | dk | max | min | k | max | min | s | Nominal Size | t | min | b | min | | 0.875 | 1.000 | 1.125 | 1.250 | 1.375 | 1.500 | 1.750 | 2.000 | 2.250 | 2.500 | 2.750 | 3.000 | 3.250 | 3.500 | 3.750 | 4.000 | 9.0 | 8.0 | 7.0 | 7.0 | 6.0 | 6.0 | 5.0 | 4.5 | 4.5 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 14.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | - | - | - | - | - | - | - | - | - | - | 20.0 | 20.0 | 18.0 | 18.0 | 18.0 | 18.0 | - | - | - | - | - | - | - | - | - | - | 0.875 | 1.000 | 1.125 | 1.250 | 1.375 | 1.500 | 1.750 | 2.000 | 2.250 | 2.500 | 2.750 | 3.000 | 3.250 | 3.500 | 3.750 | 4.000 | 0.8647 | 0.9886 | 1.1086 | 1.2336 | 1.3568 | 1.4818 | 1.7295 | 1.9780 | 2.2280 | 2.4762 | 2.7262 | 2.9762 | 3.2262 | 3.4762 | 3.7262 | 3.9762 | 1.312 | 1.500 | 1.688 | 1.875 | 2.062 | 2.250 | 2.625 | 3.000 | 3.375 | 3.750 | 4.125 | 4.500 | 4.875 | 5.250 | 5.625 | 6.000 | 1.293 | 1.479 | 1.665 | 1.852 | 2.038 | 2.224 | 2.597 | 2.970 | 3.344 | 3.717 | 4.090 | 4.464 | 4.837 | 5.211 | 5.584 | 5.958 | 0.875 | 1.000 | 1.125 | 1.250 | 1.375 | 1.500 | 1.750 | 2.000 | 2.250 | 2.500 | 2.750 | 3.000 | 3.250 | 3.500 | 3.750 | 4.000 | 0.864 | 0.988 | 1.111 | 1.236 | 1.360 | 1.485 | 1.734 | 1.983 | 2.232 | 2.481 | 2.730 | 2.979 | 3.228 | 3.478 | 3.727 | 3.976 | 0.750 | 0.750 | 0.875 | 0.875 | 1.000 | 1.000 | 1.250 | 1.500 | 1.750 | 1.750 | 2.000 | 2.250 | 2.250 | 2.750 | 2.750 | 3.000 | 0.432 | 0.495 | 0.557 | 0.620 | 0.682 | 0.745 | 0.870 | 0.995 | 1.120 | 1.245 | 1.370 | 1.495 | 1.620 | 1.745 | 1.870 | 1.995 | 2.25 | 2.50 | 2.81 | 3.12 | 3.44 | 3.75 | 4.38 | 5.00 | 5.62 | 6.25 | 6.88 | 7.50 | 8.12 | 8.75 | 9.38 | 10.00 | |
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 |
Finish
PLAIN ZP YZP BLACK HDG DACROMET GEOMET CHROME NICKEL AND SO ON
PACKING
QBH BULK
20-25KG/CTN,36CTNS/PALLET
20-30KG/BAGS,36BAGS/PALLET
ONE TON/BOXES
50KG/ IRON DRUM,12 IRON DRUMS/PALLET
QBH SMALL PACKING
Packing in small boxes according to customer’s requirements
Packing in plastic bag according to customer’s requirements
QBH PALLET TYPE
SOLID WOOD FUMIGATION PALLET
EURO Pallet
THREE SPLINT PALLET
WOODEN BOX
The advantages of QBH
- QBH brand sales to the main quality assurance.
- Years of export trade management, excellent service, word-of-mouth guarantee.
- By working with TUV,escort for quality.
- Customization of non-standard parts can be made according to customer's requirements and drawings.
- For quality customers,we can provide a certain credit period.
Product application
QBH Hex Socket head cap screws are commonly used in machine assembly for removable panels and parts. They have a round cap with a hex head and are tightened with a socket wrench drive. Longer caps are easier to see when fastened, while button and flat head caps are less likely to snag clothing or linkages. Cap screws with a black oxide or armor coat finish resist corrosion.
Company Profile
Jiaxing City Qunbang Hardware Co,ltd is a productiondesignsales and
after-sales as one of the fasteners business,The company is located
in HangjiaHu Plain,close to ShanghaiNingboZhapu ports.The
geographical position is superior,the transportation is
convenient,has created the natural superiority for the export.
The company mainly produces high-strength fasteners business, bolts
and nuts are the main,the main standard are
DIN/ANSIASME/JIS/UNI/ISO/AS/BS/GB and so on.The product massively
applies in the bridgeroadthe petroleum pipeline facilitythe wind
power generation and steel structure project. Carbon steel bolts
mainly have 4.8、5.8、6.8、8.8、10.9、12.9,nuts mainly have 4、6、8、10,the
main material of stainless steel fastener is 201304316.QBH from its
establishment to he present,after ten years of development,it is
equipped with perfect testing equipment,and SGS and TUV have a good
cooperation,each batch of products is accompanied by a 3.1 or 3.2
certificate,further escort the quality of the company.
In 2017,we registered the trademark “QBH” in the CHINA、EU、United
States,and has six fastener product patents,has obtained the
Zhejiang Province science and technology small and medium-sized
enterprise certificate as well as the ISO9001:2000 cerfiticate.With
the continuous development and expansion of the company,as well as
customer demand for product diversification,on the basis of its
original production,in order to further enhance the potential for
cooperation with customers,as well as to provide competitive
prices.Starting in 2015,QBH has taken part in several fastener
enterprises one after another,the product variety is more abundant
and the price is more advantageous,and the quality can also be well
controlled. QBH has always been to provide customers with efficient
and convenient service and quality products,and create a pleasant
trading process for customers for the mission,deeply participate in
customer construction projects and make progress together with
customers,this means that we need to provide better and more
cost-effictive solutions,so as to help customers stand out from the
competition.
QBH promises to always provide you with excellent quality,efficient
service and very competitive prices.We believe that the cooperation
between us is not only based on business,but also hope that we can
open new markets on the basis of win-win situation.And thank all
the customers in the past to give us great support and help,make us
grow up gradually,at the same time also hope that in the nere
future,and you can establish new business relations.