Medium-Strength Metric Class 8.8 Steel Flanged Hex Head Screws

Material: Carbon steel.Alloy steel.40Cr alloy steel

Standard: GB 5787&Q 180&Q 181&Q 182&ISO 15072&ISO 4162 &DIN 6921&DIN 6922&ASME B 18.2.3.4M&JIS B 1189 (Type 2)

Screw assemblies can loosen under the effect of vibration, impact, and heat expansion. To secure assemblies that are screwed together and avoid any unforeseen loosening of screws and nuts, a variety of techniques have been developed: elastic washers, Nylon rings or patches,

size interference, etc.

The most effective solution for stopping loosening is pre-coating

to ensure thread locking:

This technique comprises pre-coating the threads with a dry

thread-locking compound that only becomes active during

assembly.

Discover the Advantages of Pre-Coated Fasteners

Pre-coated fasteners replace conventional thread-locking solutions, offering incomparable technical and financial results:

 Improved performance: unparalleled vibration resistance

Facilitated design: replaces standard nuts and bolts with no need to redesign the assembly

Fast assembly: no need for washers or adhesive

Technical reliability: the amount of product deposited in the assembly is always the same

 Flawless quality: the thread-locking process cannot be forgotten

Significant assembly cost savings: high productivity in the shop or on-site Eliminates hygiene and safety issues linked to liquid adhesives

Factory coating parts achieve thread locking using pre-coated fastener parts with thread-locking compound, creating a dry patch on the screw or nut thread.

Two po

Two possible solutions:

Thread locking using a micro-encapsulated adhesive:

This technique comprises pre-coating the threads with a microencapsulated adhesive that only becomes active during assembly.

During assembly, the adhesive released by breaking the microcapsules polymerizes and bonds the threaded parts together.

This is the most efficient solution to stop slackening.

Repositionable polyamide thread-locking solution:

When the parts are screwed down, the polyamide deposited on the threads is compressed. The radial

tension caused by the elastic product deformation causes the locking action.

The locked parts can be repositioned as the polyamide deformation is reversible, allowing parts to be

screwed down and released several times.

The polyamide brings two additional functions compared with a bare screw:

1. It dampens vibrations, thereby avoiding unforeseen slackening.

2. It avoids the loss of the screw should it become slack. The thread-locking function is active immediately after screwing down.

JIS High-Strength Steel Flanged Hex Head Screws: Made to Japanese Industrial Standards, these Class 10.9 steel 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. The flange distributes pressure where the screw meets the surface, eliminating the need for a separate washer. The zinc plating provides corrosion resistance in wet environments. Head height includes the flange. Length is measured from under the flange.

Match the thread spacing of mating components. Coarse threads are the industry standard; choose these screws if you don’t know the pitch. Fine and extra-fine threads are closely spaced to prevent loosening from vibration; the finer the thread, the better the resistance.

Fiberglass Flanged Hex Head Screws: Made from polyurethane reinforced with glass fiber, these screws are chemical and oil resistant, nonconductive, and lightweight. The flange distributes pressure where the screw meets the surface, eliminating the need for a separate washer. Head height includes the flange. Length is measured from under the flange.

Medium-Strength Metric Class 8.8 Steel Serrated-Flange Hex Head Screws: These Class 8.8 screws are suitable for fastening most machinery and equipment. Serrations under the head grip the material surface for mild vibration resistance, and the flange distributes pressure where the screw meets the surface, eliminating the need for a separate washer. The zinc plating provides corrosion resistance in wet environments. Dimensions meet DIN 6921 specifications. Head height includes the flange. Length is measured from under the flange.

High-Strength Metric Steel Serrated-Flange Hex Head Screws: Choose these steel screws for high-stress applications, such as valves, pumps, motors, and automotive suspension systems. They are about 10% stronger than medium-strength steel screws. Serrations under the head grip the material surface for mild vibration resistance, and the flange distributes pressure where the screw meets the surface, eliminating the need for a separate washer. The black-oxide finish provides mild corrosion resistance in dry environments. Head height includes the flange. Length is measured from under the flange.

High-Strength Grade 8 Steel Serrated-Flange Hex Head Screws: About 20% stronger than medium-strength steel screws, these Grade 8 steel screws can be used in high-stress applications, such as valves, pumps, motors, and automotive suspension systems. Serrations under the head grip the material surface for mild vibration resistance, and the flange distributes pressure where the screw meets the surface, eliminating the need for a separate washer. The material meets SAE J429 specifications for quality. Dimensions meet IFI 111 specifications. Grade 8 steel hex head screws are marked with six radial lines. Head height includes the flange. Length is measured from under the flange.

Black-phosphate steel screws are mildly corrosion-resistant in dry environments.

Zinc-plated and zinc yellow-chromate-plated steel screws are corrosion-resistant in wet environments.