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.

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Blind Bolt Fixing

Find Your Standard Blind Bolt

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Blind Bolt Thickness Diagram
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Blind Bolt

Technical Data Explained

Blind Bolt Technical Data - fixing terms

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
(mm)
Hole
Diameter
(mm)
Fixing
Thickness
Min
(mm)
Max
(mm)
Anchor
Clearance
(mm)
Depth
Clearance
(mm)
Minimum
Hole Centers
(mm)
BB0850ZF M8 x 50 50 9 9 24 19 25 20
BB1060ZF M10 x 60 40 11 10 29 23 30 20
BB1095ZF M10 x 95 20 11 25 64 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 56 65 72 75
#Property Class 10.9 means fuf = 1000 MPa
*We strongly recommend the use of our installation gauges when installing these bolts

Blind Bolt Product Specification - Hot Dip Galvanised - Property Class 10.9#

Product Code Bolt Size Box
Qty
Hole
Diameter
(mm)
Fixing
Thickness
Min
(mm)
Max
(mm)
Anchor
Clearance
(mm)
Depth
Clearance
(mm)
Minimum
Hole Centers
(mm)
BB1270HDG M12 x 70 20 13 12 33 26 35 25
BB12120HDG M12 x 120 25 13 30 84 26 35 25
BB12180HDG M12 x 180 20 13 80 143 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 55 132 36 43 35
GBB20110HDG M20 x 110* 10 22 21 52 44 56 48
GBB20140HDG M20 x 140* 8 22 21 82 44 56 48
GBB20180HDG M20 x 180* 10 22 80 120 44 56 48
GBB20250HDG M20 x 250* 10 22 130 190 44 56 48
GBB24130HDG M24 x 130* 5 26 21 62 53 64 60
#Property Class 10.9 means fuf = 1000 MPa
*We strongly recommend the use of our installation gauges when installing these bolts

Hot Dip Galvanised & Zinc Flake Blind Bolt - Property Class 10.9# - NZS 3404:1997

Diameter

Tension Capacity

Shear Capacity
Over Thread

Shear Capacity Over Slot

Recommended
Tightening
Torque
ɸNtf (kN) ɸVf (kN) ɸVf (kN) (Nm)
M8 9.8 14.6 9.1 15
M10 14.1 23.2 19.0 24
M12 22.4 33.7 26.4 30
M14 34.8 46.7 34.8 34
M16 38.8 62.7 49.1 50
M20 71.4 97.9 76.1 65
M24 116.7 141.0 105.4 75
M30 174.5 224.0 164.6 85
#Property Class 10.9 means fuf = 1000 MPa

These are design values and should be compared directly with the design shear force Vf* and design tension force Ntf*.
Bolt bearing capacity should be calculated in accordance with NZS 3404 clause 9.3.2.4.1, using the nominal diameter of the bolt. Combined shear and tension should satisfy the following equation:

NZ 3404 1 blind bolt Blindbolt NZ

using the values of ɸVf and ɸNtf from the table above.

The design tension resistances make no allowance for the deformation of the connected parts, which is likely to be the critical check when connecting thin material.

 

Stainless Steel Blind Bolts Technical Data

Blind Bolt Product Specification Stainless Steel A4-70

Product Code Bolt
Size
Box
Qty
Hole
Diameter
(mm)
Fixing
Thickness
Min
(mm)
Max
(mm)
Anchor
Clearance
(mm)
Depth
Clearance
(mm)
Minimum
Hole Centers
(mm)
BB0850A4ASM M8 x 50 50 9 9 24 19 25 20
BB1060A4ASM M10
x 60
40 11 10 29 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 installation gauges when installing these bolts

Important Note

The design values for the shear capacity ɸVf and tension capacity ɸNtf of Blind Bolts given in the following table may be used in conjunction with designs completed to NZS 3404:1997 or AS 4100:1998.

Stainless Steel Blind Bolt Design to BS 5950

Diameter Tension Capacity
Shear Capacity
Over Thread
Shear Capacity Over Slot
Recommended
Tightening Torque
ɸNtf (kN) ɸVf (kN) ɸVf (kN) (Nm)
M8 5.3 12.3 7.8 15
M10 12.7 19.5 13.3 22
M12 22.0 28.3 18.4 28
M16 42.9 52.8 36.1 45
Important Note: NZS 3404 does not cover the design of stainless steel. The values on this table have been determined in accordance with EN 1993-1-8, which is compatible with NZS 3404.

These are design values and should be compared directly with the design shear force Vf* and design tension force Ntf*.
Bolt bearing capacity should be calculated in accordance with NZS 3404 clause 9.3.2.4.1, using the nominal diameter of the bolt. Combined shear and tension should satisfy the following equation:

NZ 3404 1 blind bolt Blindbolt NZ

using the values of ɸVf and ɸNtf from the table above.

The design tension resistances make no allowance for the deformation of the connected parts, which is likely to be the critical check when connecting thin material.

Blind Bolt

Testing Data Explained

Blind Bolt Technical Data - fixing terms

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

Blind Bolt Technical Data - fixing terms

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 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