the standard

Blind Bolt

Our clients are constantly devising new demands, uses and applications for the incredibly versatile Blind Bolt.

We meet this demand by manufacturing a range of different sizes, all designed to save time and money. The blind fixings which existed before the Blind Bolt have been rendered obsolete by the innovative solutions it offers.

The Blind Bolt Fixings

Its versatility and effectiveness mean that architects and builders can approach their work in entirely new ways, taking advantage of the ease with which they can now fix into a box section or girder cavity. It also allows clients to work simply and save time and, usually, money on their projects. We created the Blind Bolt and even we are amazed by the innovative ways in which our clients use it. Go to our news page to learn more about these new ideas and the products they’ve helped to inspire.

For detailed information on installation or removal, please view our Blind Bolt Installation and removal guide Blind Bolt Fitting Instructions

If you’d like to discuss your project and the way in which you could make use of Blind Bolt products, get in touch and speak to a member of the BlindBolt team by using our quick and easy contact form below. You can also contact a member of our friendly team today on +61 3 9757 4989 or by emailing us at sales@blindbolt.com.au.

Blind Bolt Fixing
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Technical Data Explained
Testing Data Explained
Fixing Terms
Fitting Instructions
SCI Report
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Find Your Standard Blind Bolt

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Blind Bolt Thickness Diagram

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Blind Bolt

Technical Data Explained

Blind Bolt Testing Terms
Technical Data Download
Install Information Download

NOTE: All dimensions are in mm unless stated otherwise.

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

Blind Bolt Product Specification - Zinc Flake 1000Hr SSP - Property Class 10.9
Product Code Bolt Size Box
Qty		 Hole
Diameter
Fixing
Thickness
Min Max
Anchor
Clearance		 Depth
Clearance		 Minimum
Hole Centers
BB0850ZF M8 x 50 50 9 9 24 19 25 20
BB1060ZF M10 x 60 40 11 10 30 23 30 20
BB1095ZF M10 x 95 20 11 25 65 23 30 20
BB10130ZF M10 x 130 20 11 55 100 23 30 20
BB1270ZF M12 x 70 20 13 12 35 26 35 25
GBB30140ZF M30 x 140* 5 32 27 60 65 72 75
* We strongly recommend the use of our safety gauges when installing these bolts

Blind Bolt Product Specification - Hot Dip Galvanised - Property Class 10.9
Product Code Bolt Size Box
Qty		 Hole
Diameter
Fixing
Thickness
Min Max
Anchor
Clearance		 Depth
Clearance		 Minimum
Hole Centers
BB1270HDG M12 x 70 20 13 12 35 26 35 25
BB12120HDG M12 x 120 25 13 30 85 26 35 25
BB12180HDG M12 x 180 20 13 80 140 26 35 25
GBB1475HDG M14 x 75* 20 15 14 35 32 38 32
GBB14125HDG M14 x 125* 20 15 28 82 32 38 32
GBB14185HDG M14 x 185* 20 15 75 142 32 38 32
GBB1690HDG M16 x 90* 20 17 13 43 36 43 35
GBB16130HDG M16 x 130* 15 17 40 75 36 43 35
GBB16180HDG M16 x 180* 10 17 55 125 36 43 35
GBB20110HDG M20 x 110* 10 22 21 56 44 56 48
GBB20140HDG M20 x 140* 8 22 21 86 44 56 48
GBB20180HDG M20 x 180* 10 22 80 120 44 56 48
GBB20250HDG M20 x 250* 10 22 130 185 44 56 48
GBB24130HDG M24 x 130* 5 26 21 62 53 64 60
* We strongly recommend the use of our safety gauges when installing these bolts

Important Note

The below tension resistances make no allowance for the deformation or yield of the connected parts. An appropriate design model for connections in hollow sections can be found in Joints in Steel Construction: Simple Connections.

SCI Report
SCI Calculation Worked Example
SCI Report 2020 Update

Blind Bolt Design Capacities NZS 3404:1997 or AS 4100:1998
Diameter Tension Capacity
Φ'Ntf (kN)		 Shear Capacity
Over Thread
 Φ'Vf (thread) (kN)		 Shear Capacity
Over Slot
Φ'Vf (slot) (kN)		 Recommended
Tightening
Torque (Nm)
M8 6.9 14.6 11.1 15
M 10 12.9 23.2 19.0 24
M
12		 18.8 33.7 26.3 30
M 16 40.1 62.7 51.5 50
M
20		 57.8 97.9 76.1 65
M 24 82.3 141.0 105.4 75

Important Note

The above tension resistances make no allowance for the deformation or yield of the connected parts. An appropriate design model for connections in hollow sections can be found in Joints in Steel Construction: Simple Connections.

The bearing capacity of the ply should be calculated in accordance with the design Standard, based on the nominal diameter df of the bolt. No reduction for the slot is necessary. Bolts subject to combined shear and tension should be verified in accordance with the design Standard, using the values of Φ'Vf (slot) and Φ'Ntf from the table above. The above design values were prepared by SCI, UK, following a program of tests. Design values verified by HERA, NZ are shown below.

Diameter Tension Capacity

Φ'Ntf (kN)

 Shear Capacity
Over Slot
Φ'Vf (slot) (kN)
M 10 12.0 20.6
M 20 63.7 122.5
M 24 86.7 202.6
Important Note: The above tension resistances make no allowance for the deformation or yield of the connected parts. An appropriate design model for connections in hollow sections can be found in Joints in Steel Construction: Simple Connections

Important Note

The above tension resistances make no allowance for the deformation or yield of the connected parts. An appropriate design model for connections in hollow sections can be found in Joints in Steel Construction: Simple Connections.

SCI Report
SCI Calculation Update 2020
SCI Calculation Worked Example

Blind Bolt Product Specification Stainless Steel A4-70 
Product Code Bolt
Size		 Box
Qty		 Hole
Diameter
Fixing
Thickness
Min Max
Anchor
Clearance		 Depth
Clearance		 Minimum
Hole Centers
BB0850A4ASM M8 x 50 50 9 9 24 19 25 20
BB1060A4ASM M10
x 60		 40 11 10 30 23 30 20
BB1290A4ASM M12 x 90 20 13 12 55 26 35 25
GBB16100A4ASM* M16
x 100		 20 17 13 53 36 43 35
* We strongly recommend the use of our safety gauges when installing these bolts

Stainless Steel Blind Bolts Technical Data

Stainless Steel Blind Bolt Design to BS 5950
Diameter Tension Capacity
Pt (kN)		 Shear Capacity
Over Thread
Ps, thread (kN)		 Shear Capacity Over Slot
Ps, slot (kN)		 Bearing Capacity
in 10mm Plate		 Recommended
Tightening
Torque (Nm)
S275
Pb, (kN)		 S355
Pb, (kN)		  
M 8 5.3 10.3 6.5 20.7 24.8 15
M
10		 12.7 16.2 11.1 27.6 33.0 22
M 12 21.4 23.6 15.4 32.2 38.5 28
M
16		 42.8 44.0 30.1 46.0 55.0 45

These capacities are suitable for design to BS 5950-1 and can be compared directly with factored loads. Bearing resistances for different thicknesses can be calculated by scaling the values given in proportion to the thickness, but should only be used when the end distance is greater than 2d.

Bolts subject to combined tension and shear should satisfy the following expression:

tensionshear top ss white technical data Blindbolt UK

Stainless Steel Blind Bolt Design to BS EN 1993
Diameter Tension Resistance
Ft,Rd (kN)		 Shear Resistance
Over Thread
Fv,Rd thread(kN)		 Shear Resistance
Over Slot
Fv,Rd slot (kN)		 Bearing Capacity
in 10mm Plate		 Recommended
Tightening
Torque (Nm)
S275
Fb,Rd(kN)		 S355
Fb,Rd(kN)		  
M 8 5.3 12.3 7.8 65.6 75.2 15
M
10		 12.7 19.5 13.3 82.0 94.0 22
M 12 22.0 28.3 18.4 98.4 112.8 28
M
16		 42.9 52.8 36.1 131.2 150.4 45

These design resistances are suitable for design to BS EN 1993 and can be compared directly with design loads. The quoted bearing resistances assume k1 = 2.5 and αb = 1.0. For different arrangements the bearing resistance should be calculated using the expression in Table 3.4 of BS EN 1993-1-8, with d as the nominal diameter of the blind bolt.

Bolts subject to combined tension and shear should satisfy the following expression:

ss calc bot 281 29 technical data Blindbolt UK

SCI Report
SCI Calculation Update 2020

Blind Bolt

Testing Data Explained

Blind Bolt Testing Terms

Blind Bolt is a versatile fixing solution which offers multiple combinations in any particular situation. Different uses can lead to the measured strength of the Blind Bolt varying, however.

The tensile strength of the Blind Bolt is constant, but the shear strength can change in line with the thickness of the materials being fixed.

A summary of the variations involved is set out below, and more detailed information is contained in our technical data sheets.

If you have further questions on the strength and testing of Blind Bolts please get in touch with us. Use the contact details at the bottom of the page or click here to send us an email.

Blind Bolt

Fixing Terms Explained

Blind Bolt Testing Terms

The Blind Bolt has an innovative and unique design. This means that anyone using them has to be aware of exactly how the dimensions of the bolts are measured, and the way in which these measurements are used during fitting.

On the menu above you’ll see a pictorial representation of these measurements, while the details are set out below.

If you have further questions on the fixing terms of Blind Bolts please get in touch with us.

Use the contact details at the bottom of the page or click here to send us an email.

Blind Bolt

Fitting Instructions
Installations & Removal Videos

The following videos visually represent both the detailed installation and removal of the Blind Bolt.

Blind Bolt Horizontal
Installation & Removal

Blind Bolt Horizontal Installation Video

Blind Bolt
Horizontal Installation

Blind Bolt Horizontal Installation Video

Blind Bolt
Horizontal Removal

Removal Installation Video

Blind Bolt Downward Installation

Blind Bolt Downward Installation

Blind Bolt Vertical Removal

Blind Bolt Vertical Removal Video

Blind Bolt Fitting Instructions (PDF Download)

Blind Bolt

SCI Report