the

Thin Wall Bolt

Thin Wall Bolts or TW Bolts were developed to address the need for a blind fixing to be used into lightweight steel sheet or cladding material.

Thin Wall Fasteners

After installation, a neat, low profile head is left with no stud. The Thin Wall bolt has a strong shear capacity. It is quick and easy to install

  • No over-sized hole required
  • Finished with zinc electroplate giving excellent protection
  • Increased assembly efficiency

For detailed information on installation or removal, please view our installation and removal guide, TW Fitting Instructions

Please visit our News page for information about new products and applications. Alternatively please contact us using the details below to discuss your projects and how we could help.

Thin Wall Bolt

Thin Wall Bolt

Technical Data

Thin Wall Bolt Specifications

NOTE: All dimensions are in mm unless stated otherwise.

The Blind Bolt Company reserve the right to change these technical details without notice.

Thin Wall Bolt Product Specification - Zinc Nickel

PRODUCT
CODE
HOLE
DIAMETER
DEPTH
CLEARANCE
CLAMPING
RANGE
(mm) (mm) MIN (mm) MAX (mm)
TW5ZF-10 8 35 2 10
TW5ZF-16 8 40 8 16
TW6ZF-10 10 35 2 10
TW6ZF-16 10 40 8 16
TW8ZF-10 13 45 2 10
TW8ZF-16 13 50 8 16

Design Resistance for TW Type Blind Bolts Design to BS 5950 - Zinc Nickel

TW Bolt
Size
Set Screw
Diameter
(mm)
Collar Outside
Diameter
(mm)
Hole
Diameter
(mm)
Shear
Resistance
(kN)
Tension
Resistance
(kN)
TW5 5 7.8 8 13.2 4.8
TW6 6 9.5 10 19.5 14.1
TW8 8 12.6 13 34.5 25.6

Design resistances in shear and tension are presented above. The resistance values may be compared directly with the ultimate loads applied to the fixing.

The bearing resistance may be calculated in accordance with the design standard, based on the external diameter of the collar, as given above.

Fixings subject to combined shear and tension should be verified in accordance with the design standard, using the design resistances presented above.

If tension is applied to a fixing in a relatively thin wall application, the deformation of the connected material should be considered at serviceability (working loads) and at the ultimate limit state, as deformation is likely to be the limiting feature of the connection.

Design Resistance for TW Type Blind Bolts Design to BS EN 1993 - Zinc Nickel

TW Bolt
Size
Set Screw
Diameter
(mm)
Collar Outside
Diameter
(mm)
Hole
Diameter
(mm)
Shear
Resistance
(kN)
Tension
Resistance
(kN)
TW5 5 7.8 8 15.9 4.8
TW6 6 9.5 10 23.4 10.1
TW8 8 12.6 13 41.4 18.4

Design resistances in shear and tension are presented above. The resistance values may be compared directly with the ultimate loads applied to the fixing.

The bearing resistance may be calculated in accordance with the design standard, based on the external diameter of the collar, as given above.

Fixings subject to combined shear and tension should be verified in accordance with the design standard, using the design resistances presented above.

If tension is applied to a fixing in a relatively thin wall application, the deformation of the connected material should be considered at serviceability (working loads) and at the ultimate limit state, as deformation is likely to be the limiting feature of the connection.

Stainless Steel Thin Wall Bolts

Thin Wall Bolt Product Specification Stainless Steel A2-70

PRODUCT
CODE
HOLE
DIAMETER
DEPTH
CLEARANCE
CLAMPING
RANGE
(mm) (mm) MIN (mm) MAX (mm)
TW5SS-10 8 35 2 10
TW5SS-16 8 40 8 16
TW6SS-10 10 35 2 10
TW6SS-16 10 40 8 16
TW8SS-10 13 45 2 10
TW8SS-16 13 50 8 16

Design Resistance for TW Type Blind Bolts Design to BS 5950 - Stainless Steel A2-70

TW Bolt
Size
Set Screw
Diameter
(mm)
Collar Outside
Diameter
(mm)
Hole
Diameter
(mm)
Shear
Resistance
(kN)
Tension
Resistance
(kN)
TW5 5 7.8 8 11.6 7.0
TW6 6 9.5 10 17.3 9.8
TW8 8 12.6 13 30.4 17.9

Design resistances in shear and tension are presented above. The resistance values may be compared directly with the ultimate loads applied to the fixing.

The bearing resistance may be calculated in accordance with the design standard, based on the external diameter of the collar, as given above.

Fixings subject to combined shear and tension should be verified in accordance with the design standard, using the design resistances presented above.

If tension is applied to a fixing in a relatively thin wall application, the deformation of the connected material should be considered at serviceability (working loads) and at the ultimate limit state, as deformation is likely to be the limiting feature of the connection.

Design Resistance for TW Type Blind Bolts Design to BS En 1993 -
Stainless Steel A2-70

TW Bolt
Size
Set Screw
Diameter
(mm)
Collar Outside
Diameter
(mm)
Hole
Diameter
(mm)
Shear
Resistance
(kN)
Tension
Resistance
(kN)
TW5 5 7.8 8 14.0 5.0
TW6 6 9.5 10 20.8 7.1
TW8 8 12.6 13 36.4 12.9

Design resistances in shear and tension are presented above. The resistance values may be compared directly with the ultimate loads applied to the fixing.

The bearing resistance may be calculated in accordance with the design standard, based on the external diameter of the collar, as given above.

Fixings subject to combined shear and tension should be verified in accordance with the design standard, using the design resistances presented above.

If tension is applied to a fixing in a relatively thin wall application, the deformation of the connected material should be considered at serviceability (working loads) and at the ultimate limit state, as deformation is likely to be the limiting feature of the connection.

Thin Wall Bolt

Fixing Data Explained

Thin Wall Bolt testing data explained - thin wall bolt technical data

Due to the unique properties of the TW Bolt there are certain operation criteria that must be met to ensure its successful application. These dimensions are outlined below, please use the menu above the picture to isolate each dimension and testing term to view a brief description.

However, if there is anything that you are unsure about please feel free to contact us on the number at the top of your screen or send us an e-mail.

What Is Minimum Clamping Range

This is the minimum distance that the bolt is able to clamp.

This is calculated from the overall thickness of all materials being clamped.

What Is Maximum Clamping Range

This is the maximum distance that the bolt is able to clamp.

This is calculated from the overall thickness of all materials being clamped.

The dimensions given are those of the standard bolt, however, the maximum fixing thickness can be greatly extended using a kit of extension sleeves.

Please contact us for more specific information

What Is Tension Resistance

This is the ultimate pullout force required for the bolt to fail when under a tensile load.

What Is Depth Clearance

Depth Clearance is the minimum distance required within a cavity to allow the Thin Wall Bolt's legs to deploy.

Careful attention must be payed to this criteria when fixing into Steel Hollow Sections to prevent the bolt reaching the opposite section wall before the bolt has been installed correctly.

Thin Wall Bolt

Fitting Instructions
Installations & Removal Videos

The following videos visually represents the detailed installation of the Thin Wall Bolt.

Fitting Instructions Video Blind Bolt

Blind Bolt

SCI Report