Best current price£8.36from The Range
Shopping.co.uk recommended and popular offers
The Range£8.36Visit shop Unifix Grade 8.8 Ht Hexagon Bolts Din 931 S/Col - M6 X 40 - &Mhb06 040 000 - Grey
Visit shop46 offers from £8.36 - £68.63
View price history by clicking the chart icon.
This guide is for engineers, construction professionals, and DIY enthusiasts requiring robust fastening solutions. The Unifix Grade 8.8 HT Hexagon Bolts offer high tensile strength for demanding applications, ensuring secure and durable connections. A key consideration is ensuring correct torque settings to maximize their high-tensile capabilities.
| Colour | Black |
|---|---|
| Model Part Number | 5014196283647 |
| Brand | Unifix |
'Grade 8.8' refers to the bolt's mechanical properties, indicating its minimum tensile strength (800 MPa) and yield strength (640 MPa). 'HT' stands for High Tensile, reinforcing its suitability for high-strength applications.
The exact torque depends on the specific application, lubrication, and the type of nut used. However, a general reference torque for an M30 Grade 8.8 bolt with a standard nut and washer is approximately 1550 Nm. Always consult engineering specifications or a torque chart for your specific project.
DIN 931 specifies Hexagon head bolts with shank. 'S/Col' likely refers to a variant, potentially indicating a 'shank' or 'collar' feature, which can impact load distribution or assembly characteristics. Consult detailed DIN standards for precise specifications.
The black finish offers some corrosion resistance, but for long-term or harsh outdoor environments, additional protective measures or different materials like galvanised steel or stainless steel might be necessary.
You will need a socket wrench or spanner that fits the M30 hex head (typically 46mm). A torque wrench is highly recommended for applying the correct tension.
Yes, their Grade 8.8 High Tensile rating makes them specifically suitable for structural and load-bearing applications where significant strength is required.
Higher grade numbers indicate higher tensile and yield strength. Grade 8.8 bolts are significantly stronger than lower grades (like Grade 4.6 or 5.8) and are designed for more demanding applications.
Ensure you are using the correct size wrench or socket (46mm for M30). Do not overtighten beyond the recommended torque. Check if the nut or thread is damaged.
Verify that the holes are clean, free of debris, and correctly aligned. Ensure the bolt diameter (M30) is appropriate for the hole size. Deburr the edges of the holes if necessary.
This usually indicates overtightening beyond the bolt's tensile strength limit or a manufacturing defect. Ensure you are using a calibrated torque wrench and adhering to the specified torque values for Grade 8.8 bolts. If a defect is suspected, discontinue use and contact the supplier.
The black finish provides moderate protection. For environments with high humidity or exposure to chemicals, consider applying a protective coating (e.g., wax, paint) or using stainless steel or galvanised bolts for long-term applications.
Setup: These bolts are designed for direct installation. Ensure the mating holes in the components to be joined are clean, deburred, and of the correct size (typically matching the M30 thread). Use appropriate washers (e.g., hardened flat washers) under the bolt head and nut to distribute the load evenly. Tighten the bolt using a socket wrench or spanner of the correct size (typically 46mm for M30 hex heads), applying the recommended torque for Grade 8.8 bolts.
Compatibility: The M30 x 220mm dimension and M30 thread pitch are standard. Ensure compatibility with M30 nuts and any existing or planned M30 threaded holes. They are designed to work with materials capable of withstanding the high clamping forces generated by Grade 8.8 bolts.
Care: While the black finish offers some protection, for prolonged outdoor use or in corrosive environments, consider applying additional protective coatings or using galvanised alternatives. Store bolts in a dry place to prevent premature corrosion. Regularly inspect critical connections for any signs of wear, damage, or corrosion.
