Hexagonal Bolt - M20 x 100 - Silver
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The RangeUnifix Grade 8.8 Ht Hexagon Bolts Din 931 Bzp - M20 X 100 - Box Of 10 - Grey
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eBayUnifix Grade 8.8 HT Hexagon Bolts M20 x 100 - Box of 10
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DebenhamsUnifix Unisex Silver Grade 8.8 Ht Hexagon Bolts - Box Of 10 In
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B&QB&Q - M20 X 100 Hexagonal Bolt High Tensile 8.8 Din 931 Bright Zinc Plated (Bzp) 5 Pack
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Product Information
Full details
This guide is for engineers, construction professionals, and DIY enthusiasts requiring robust fastening solutions. The M20 x 100mm Hexagonal Bolt offers high tensile strength and corrosion resistance, making it ideal for demanding applications. A key consideration is the specific DIN 931 standard, which ensures compatibility but requires matching fittings.
All features
| Colour | Silver |
|---|---|
| Model Part Number | MHB20100081 |
| Brand | Generic Fasteners |
Extended Product Information
FAQs
What does 'M20 x 100' mean?
'M20' refers to the metric thread diameter of 20mm. '100' refers to the length of the bolt in millimeters, measured from under the head to the tip of the bolt.
What is BZP finish and CR3+ standard?
BZP stands for Bright Zinc Plated. It's a common finish that provides a bright, shiny appearance and offers good resistance to corrosion. CR3+ refers to a trivalent chromium passivation treatment, which is an environmentally friendlier alternative to older hexavalent chromium plating, enhancing corrosion resistance further.
What size spanner or socket do I need for this bolt?
For an M20 hexagonal bolt head, you typically need a 30mm or 32mm spanner or socket, depending on manufacturing tolerances.
Is this bolt suitable for outdoor use?
Yes, the BZP finish provides good corrosion resistance, making it suitable for many outdoor applications. However, for extremely harsh or marine environments, stainless steel might be a more appropriate choice.
What is the tensile strength of a Grade 8.8 HT bolt?
A Grade 8.8 HT bolt has a minimum tensile strength of 800 MPa (Megapascals) and a minimum yield strength of 640 MPa. This indicates its suitability for high-stress applications.
Can I use this bolt with a standard M20 nut?
Yes, as this bolt conforms to the DIN 931 standard, it is designed to be compatible with standard M20 nuts and washers.
How many bolts are included in this purchase?
This specific listing is for 5 pieces/s of the M20 x 100mm Hexagonal Bolt.
Troubleshooting
Bolt is difficult to thread into the nut or component.
Check for cross-threading. Ensure the M20 nut and bolt threads are clean and undamaged. Verify that both the bolt and nut are M20 standard.
Bolt head stripping during tightening.
Use the correct size spanner or socket (typically 30mm or 32mm for M20). Ensure the tool is fully seated on the bolt head. Apply steady, even pressure.
Bolt showing signs of rust or corrosion.
The BZP finish provides protection, but prolonged exposure to harsh conditions can lead to surface rust. For critical applications, consider using stainless steel or applying a protective coating. Clean surface rust with a wire brush and reapply a suitable protective coating if necessary.
Bolt breaking under load.
This may indicate the load exceeds the bolt's Grade 8.8 HT rating or that the bolt is fatigued. Re-evaluate the application's load requirements. Ensure the correct grade and size of bolt are being used for the intended purpose.
Pros and Cons
Pros
- Excellent corrosion resistance due to BZP finish.
- High tensile strength suitable for demanding structural loads.
- Hexagonal head allows for secure tightening in tight spaces.
- Standardized DIN 931 specification ensures broad compatibility.
- Durable construction for long-term reliability.
Cons
- Requires appropriate tools for tightening and loosening.
- May be oversized for very light-duty applications.
- BZP finish can be scratched, potentially affecting corrosion resistance in harsh conditions.
- Requires compatible M20 nuts and washers.
- Specific to DIN 931 standard, not universally interchangeable with all bolt types.
Setup, Compatibility & Care
Setup:
- Ensure the mating hole is correctly sized for an M20 bolt (typically around 21-22mm clearance hole).
- Thread the bolt through the components to be joined.
- Apply the appropriate M20 nut and washer(s).
- Tighten securely using a 30mm or 32mm spanner or socket, applying the required torque according to engineering specifications.
Compatibility:
- This bolt conforms to DIN 931 (partially threaded hexagon head bolts). Ensure mating nuts, washers, and pre-drilled holes are also compatible with this standard.
- Compatible with standard M20 nuts and washers.
- Suitable for use with a wide range of materials including steel, wood, and thick plastics, provided the load is within the bolt's rating.
Care:
- While the BZP finish offers corrosion resistance, avoid prolonged exposure to highly corrosive environments without additional protection.
- Inspect bolts periodically for signs of wear, damage, or corrosion, especially in critical applications.
- If used in exposed environments, consider applying a suitable lubricant or anti-seize compound to the threads to prevent galling and ease future removal.