---
title: "Large square Head"
id: "9337"
type: "guides"
slug: "large-square-head"
published_at: "2026-05-07T15:46:06+00:00"
modified_at: "2026-05-18T14:11:28+00:00"
url: "https://bighead.co.uk/the-techub/guides/large-square-head/"
markdown_url: "https://bighead.co.uk/the-techub/guides/large-square-head.md"
excerpt: "Guidance on specifying large square Head customisation for bigHead fasteners, covering compatibility, load‑spreading benefits and key design considerations."
taxonomy_guide_category:
  - "Customisation guides"
---

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 › Large square Head

Customisation guides

# Large square Head

[Back to guides](../)

## Key takeaways

- You can request large square Head customisation for a range of standard bigHead studs, collars, nuts, pins, and nails.
- Large square Heads provide ~3.5× the load‑spreading area of standard Head designs.
- They provide maximised load-spreading, reducing stresses and helping prevent material failure in thin or lower-stiffness substrates.
- Fixing lengths and thread sizes are the same as their equivalent standard products.
- Perforation patterns and Head designs are fixed (58 × 58 mm shape, 1.2 mm thickness).
- Installation strength depends on adhesive or embedment design.
- FLL values match the standard bigHead counterparts, but WLL and tightening torque recommendations may differ (available on request).
- Identified by product code **B58** (blind) or **S58** (sighted).

## Customisation scope for large square Head

This customisation replaces the standard Head component with a large square head component. It can be blind or sighted.

### Products compatible with blind large square Head (B58)

Standard lengths for externally threaded studs (M1/ SM1), by thread size:

- M4 → 12, 16, 20 and 25 mm
- M5 → 12, 16, 20, 25, 30 and 40 mm
- M6 and M8 → 12, 16, 20, 25, 30, 40, 50 and 75 mm
- M10 → 20, 25, 30 and 40 mm

Blind internally threaded collars (F2/SF2), standard collar lengths by thread size:

- M4 → 10 and 15 mm
- M5 – M10 → 10, 15 and 20 mm
- M12 → 15 and 20 mm

Unthreaded pin (M4) – carbon steel and bright zinc plate only, standard pin lengths:

- 5 mm diameter pin → 12, 20, 25, 30, and 40 mm
- Nail (SM5) – 316 stainless steel only, standard nail lengths:
- 3 mm diameter nail → 30, 50, 75, 100 and 125 mm

### Products compatible with sighted large square Head (S58)

Sighted internally threaded collars (F2/SF2), standard collar lengths by thread size:

- M4 → 5, 10 and 15 mm
- M5 and M6 → 5, 10, 15 and 20 mm
- M8 and M10 → 10, 15 and 20 mm
- M12 → 15 and 20 mm

Sighted internally threaded nuts (F1/SF1), standard nut sizes:

- M4, M5, M6, M8, M10 and M12

### Large square Head (carbon steel)

Key dimensions for carbon steel bigHead with large square Head customisation

Section view of F2/B58 bigHead large square Head customisation

Section view of F2/S58 bigHead large square Head customisation

### Large square Head (stainless steel)

Key dimensions for stainless steel bigHead with large square Head customisation

Section view of SF2/B58 bigHead large square Head customisation

Section view of SF2/S58 bigHead large square Head customisation

## What's outside the scope of large square Head customisation

Non-applicable product types:

- 45 degree loop (M7/SM7)
- 90 degree loop (M8/SM8)
- Cable tyrap

Complex requests are out-of-scope due to manufacturing constraints. Examples:

- Combining a large square Head with a non-standard fixing length
- Modifying the B50/S50 Head geometry or perforation pattern

If you have an out-of-scope request, we can work with you to create a solution –[get in touch](https://bighead.co.uk/?post_type=guides&p=9329&preview=true#contact-form)
.

## Design and performance considerations for large square Head

The large square Head has about 3.5 times the surface area of standard B32/S32 bigHead products:

- B32 = ~790 mm²
- B58 = ~2880 mm²

The large square Head has a footprint of 58 × 58 mm. The perforation hole arrangements are different for carbon steel and stainless steel variants.

### Loadability

- Fixing load limit (FLL) values match the equivalent standard products.
- Weld load limits (WLL) and tightening torque recommendations may differ to standard products. We can provide this information on request.

### Embedding and surface bonding performance

Embedding and surface bonding performance varies depending on the embedment design or adhesive. Because of this, we can’t provide simple installation strength comparisons between our standard products and large square Head designs.

If you need performance data for a large square Head customisation, [get in touch](https://bighead.co.uk/?post_type=guides&p=9329&preview=true#contact-form)
. We’ll help you explore the best options for your application.

## Specification examples for large square Head customisation

### Example 1: Carbon steel, bright zinc plate (BZP) finish

To specify an externally threaded stud, M8 × 40 mm, on a B58 Head:

- Product type: M1
- Large square Head customisation: B58
- Thread diameter: M8
- Customised thread length (L): 40 mm
- Stud material suffix: HT (carbon steel, heat treated)

**→ M1/B58 M8 × 40 HT**

### Example 2: 316 stainless steel

To specify an internally threaded nut, M10, on a sighted S58 Head:

- Material prefix: S (316 stainless steel)
- Product type: F1
- Large square Head customisation: S58
- Thread diameter: M10

**→ SF1/S58 M10**

### Example 3: Out of scope

A request for M10 × 30 mm collar (F2) on a blind B58 head is not possible through our customisation service as 30mm is not a standard product size.

Instead, we can create a solution for you through our [Create service](https://bighead.co.uk/bespoke/create/)
.

# Next steps

## Requesting a large square Head customisation

Contact us with your required product code to request a quote or confirm suitability.

If needed, we can help you define whether a large square Head is suitable for your application.

**Contact:**  
 Email: [sales@bigHead.co.uk](mailto:sales@bigHead.co.uk)
  
 Tel: +44 (0) 1202 574601

**Sales availability:**  
 Mon–Thu: 07:30–16:15 (UK)  
 Fri: 07:30–12:15 (UK)

[Get in touch](#contact-form)

## FAQs

- When should I use a large square Head instead of a standard Head? Use a large square Head when you need to maximise the load distribution – typically with thin, flexible, or low‑strength materials where a standard Head may cause localised bending, imprinting, or failure.
- Can the B58 or S58 Head design itself be modified? No, not through our customisation service. The B58/S58 designs (diameter, cropped profile, perforation layout, thickness) are fixed.
- Does using a large square Head change the strength rating of the product? Fixing load limits (FLL) remain the same as their standard counterparts. Weld load limits (WLL) and tightening torques may differ. We can provide these on request.
- Can I combine a large square Head with a non‑standard fixing length or size? Not through our customisation service – but we’d love to guide you through our [Create service](https://bighead.co.uk/bespoke/create/) and create a new solution for you.
- Can bigHead provide installation strength data for large square Head customised products? Yes, but only for application‑specific enquiries. Adhesives and embedment designs vary widely, so we can’t publish direct data comparisons between standard and customised products.

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