the standard
Blind Bolt
The versatility of the Blind Bolt means that our clients are constantly devising different applications and new uses.
The Blind Bolt Fixings
We reflect this innovation by manufacturing an increasing number of new sizes, all designed to save time and money. Blind Bolts have rendered the preceding generation of blind fixings more or less obsolete.
Find Your Standard Blind Bolt
Input the overall thickness
Blind Bolt
Technical Data Explained
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 |
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| Product Code | Bolt Size | Box Qty |
Hole Diameter |
|
Anchor Clearance |
Depth Clearance |
Minimum Hole Centers |
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| 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 |
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| Product Code | Bolt Size | Box Qty |
Hole Diameter |
|
Anchor Clearance |
Depth Clearance |
Minimum Hole Centers |
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| 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.
Blind Bolt Design Capacities NZS 3404:1997 or AS 4100:1998 |
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| 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 | |
| M10 | 12.9 | 23.2 | 19.0 | 24 | |
| M12 | 18.8 | 33.7 | 26.3 | 30 | |
| M16 | 40.1 | 62.7 | 51.5 | 50 | |
| M20 | 57.8 | 97.9 | 76.1 | 65 | |
| M24 | 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 |
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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) |
| M10 | 12.0 | 20.6 |
| M20 | 63.7 | 122.5 |
| M24 | 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 | ||
Stainless Steel Blind Bolts Technical Data
Blind Bolt Product Specification Stainless Steel A4-70 |
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| Product Code | Bolt Size |
Box Qty |
Hole Diameter |
|
Anchor Clearance |
Depth Clearance |
Minimum Hole Centers |
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| BB0850A4ASM | M8x50 | 50 | 9 | 9 | 24 | 19 | 25 | 20 | ||||
| BB1060A4ASM | M10x60 | 40 | 11 | 10 | 30 | 23 | 30 | 20 | ||||
| BB1290A4ASM | M12x90 | 20 | 13 | 12 | 55 | 26 | 35 | 25 | ||||
| GBB16100A4ASM* | M16x100 | 20 | 17 | 13 | 53 | 36 | 43 | 35 | ||||
| * We strongly recommend the use of our safety gauges when installing these bolts |
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Stainless Steel Blind Bolt Design to BS 5950 |
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| 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) |
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| S275 Pb, (kN) |
S355 Pb, (kN) |
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| M8 | 5.3 | 10.3 | 6.5 | 20.7 | 24.8 | 15 | |
| M10 | 12.7 | 16.2 | 11.1 | 27.6 | 33.0 | 22 | |
| M12 | 21.4 | 23.6 | 15.4 | 32.2 | 38.5 | 28 | |
| M16 | 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:
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Stainless Steel Blind Bolt Design to BS EN 1993 |
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| 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) |
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| S275 Fb,Rd(kN) |
S355 Fb,Rd(kN) |
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| M8 | 5.3 | 12.3 | 7.8 | 65.6 | 75.2 | 15 | |
| M10 | 12.7 | 19.5 | 13.3 | 82.0 | 94.0 | 22 | |
| M12 | 22.0 | 28.3 | 18.4 | 98.4 | 112.8 | 28 | |
| M16 | 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:
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Important Note
Note that the above tension capacities make no allowance for the deformation or yield of the supporting parts.
Blind Bolt
Testing Data Explained
Blind Bolts are incredibly versatile and can be used in a wide number of fixing combinations. This variety means that the measured strength of the Blind Bolt in question can also vary. This where the testing data comes in.
Whilst the tensile strength of the Blind Bolt is constant no matter how it is used, the shear strength varies depending upon the thickness of the materials being fixed together.
A summary of the factors involved in these variations is set out below, and for a more detailed account, you can access our technical data sheets via the menu at the top of the page.
If there are any questions remaining about the testing data, fell free to contact us with an enquiry via the contact details at the bottom of the page, or by clicking here to send an email.
Blind Bolt
Fixing Data Explained
Utilising the unique and innovative Blind Bolt system effectively means being fully aware of the way in which the dimensions of the bolt are measured and classified.
These dimensions then play a vital role in meeting the criteria for successful application.
The details of these measurements are set out below and the menu above offers pictorial representations.
If you have any more enquiries regarding the fixing terms for our blind bolts, contact us using the details given at the bottom of the page of by clicking here to send an email.
Blind Bolt
How to Fit a Blind Bolt
The best fastener is one which stays in place for a long period of time without requiring a lot of maintenance, enabling projects to be completed quickly and simply. Blind bolts offer these properties which is why they’ve become incredibly popular over just a short period.
Fitting a blind bolt isn’t just a question of twisting it into a hole, however. In order to make sure that the bolt is fitted correctly the following factors have to be considered:
- The size of the hole
- The length of the joint
- The angle
- The tools needed for the job.
If all of these factors are taken into account and the bolt fitted correctly you can be certain it won’t fail over time.
1. The Size of the Hole
Two factors are directly determined by the size of the hole, and these are the length of the grip and the length of the blind bolt itself. These are two different measurements impacting on the solidity of the joint, so both have to be taken into account. In simple terms, if a bolt is too big or too small for the hole in question it could work loose. In most cases, a supplier will provide a guide which can be used to gauge the correct length, or you could purchase grip gauges. Using a meter means that you can check which sizes are suitable after drilling a hole.
2. Choose the Best Type of Blind Bolt
The many variations of blind bolt on offer are a huge benefit, but they can also be a problem. The problem arises because it can be tricky to decide exactly which bolt is the right bolt for the job in hand. Blind Bolts ranging from hollow wall to heavy duty can be purchased online and in stores, so it’s vital to know exactly what you need before making a purchase. Success means matching the right bolt to each project. The following are examples of the properties of two bolts:
M8 diameter – tension and shear capacity of 9.8pt and 14.6ps respectively
M30 diameter – tension and shear capacity of 174.5pt and 224.0ps respectively
This means that if you’re doing a job which involves high levels of pressure the M30 would be the best choice.
3. Proper Equipment
It’s possible to install a blind bolt with just a screwdriver and lots of effort, but no matter how hard you work the joint won’t be completely flush, and this will impact on the tensile and shear strength of that bolt. To do the job properly you have to invest in hydraulic and power tools which can set the bolt in position quickly and easily. Tools of this kind won’t just provide maximum strength and efficiency, they will also provide a more professional finish to the job. If hand held tools are utilised, make sure that they apply sufficient power to the bolts.
4. If the Bolt Isn’t Fitted Correctly
The seal created by the bolt should be completely flush, and if it isn’t the bolt needs to be removed and re-fitted. In some cases it will be enough to simply loosen the bolt and push it further into the hole, creating a tighter grip. If this doesn’t work it might be worth reconsidering the type of bolt being used, as this can impact your installation. Our installation and removal videos contain more detailed information.
If utilised correctly, Blind Bolts are extremely effective while still being affordable.
5. Bolted Shut
Blind bolts offer a flexible solution, with the range of sizes on offer increasing to meet client requirements. In addition, the versatility of the bolts means that we’re always coming up with new ways in which they can be used to save clients time and money.
Interested in finding out more about our blind bolt fixings and blind bolt installation? Get in touch today and speak to a member of the Blind Bolt team today on 0800 42 52 56 or send us an email on enquiries@blindbolt.com.nz. We look forward to hearing from you.
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
Blind Bolt
Horizontal Removal
Blind Bolt Downward Installation
Blind Bolt Vertical Removal
Blind Bolt Fitting Instructions (PDF Download)
Blind Bolt
SCI Report
