How To Install And Remove A Blind Bolt

Blind bolts come in six diameters and in varying lengths. To install a bolt, you need to know the hole diameter necessary to drill into the plates in which you are placing the bolt.

Here is a chart describing the proper hole diameter for each size bolt.

Bolt Part Number / Hole Diameter

M8 = 9 mm or 11/32”

M10 = 11 mm or 7/16”

M12 = 13 mm or ½”

M14 = 15mm or 9/16”

M16 = 17 mm or 11/16”

M20 = 22 mm or 13/16”

M24 = 26 mm or 1”

M30 = 32mm or 1-1/4”

Horizontal Installation

Items you will need to install the blind bolt include:

  • Wrench
  • Screwdriver
  • Installation Gauge (available on diameters M14 and larger)

There are six steps involved in installing a blind bolt.

  1. Using the chart above, determine the appropriate hole diameter that you need for the blind bolt size or part number you are using. Drill a fixing hole in the plate that is the proper hole diameter of the blind bolt you are using.
  2. A nut should be included with the blind bolt.  Attach the nut flush with the bolt end and insert the blind bolt into the fixing hole. Take note that the position of the indicator mark on the head of the blind bolt is correct for insertion.
  3. Rotate the blind bolt 180 degrees to release its locking anchor.
  4. Using a proper screwdriver, brace the blind bolt to prevent it from rotating.
  5. Use a suitable spanner to tighten the nut of the blind bolt.
  6. For blind bolts that are part numbers M14 and above. After tightening the nut by hand, use the installation gauge to ensure that the anchor of the bolt is properly deployed. To achieve this, fully insert the legs into the bolt’s lateral grooves.  Take note that the head of the safety gauge sits flush on the head of the bolt. If deployment is successful, there should not be a gap present. If there is a gap, repeat step 3.

Downward Installation

A blind bolt downward installation can be achieved in six steps.

  1. Use the chart above to determine the appropriate hole diameter that you need for the blind bolt size or part number you are using. Drill a fixed hole in the plate that is the proper hole diameter of the blind bolt you are using.
  2. Loosely fit the blind bolt’s nut and fully insert the bolt into the fitting hole.
  3. Spin the blind bolt quickly by hand to allow its anchor to drop and tighten. Tighten the bolt’s nut.
  4. Use an appropriate screwdriver to insert the bolt so that it can’t rotate.
  5. Tighten the nut with the proper spanner.
  6. For M14 blind bolts and above, use the installation gauge to fully insert the legs into the bolt’s lateral grooves. Take not that the installation gauge sits flush on the head of the blind bolt. If there is a gap, repeat step 3.

Blind Bolt Removal

Horizontally removing a blind bolt can be achieved in three steps.

  1. Loosen but don’t remove the fixing nut of the blind bolt.
  2. Push the blind bolt further into the fixing hole.
  3. Hand twists the blind bolt to retract the anchor into the body of the bolt. This allows the bolt to be removed from the fixing hole.

No doubt it is obvious to professionals who deal with fasteners that one size does not fit all.  You need to select the proper fastener for the job.

The staff at AbraFast.com is knowledgeable of the advantages and disadvantages of every fastener we carry. So you can be assured that we will direct you to the proper fastener for the job at hand.

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