I'm trying to hang a pull up bar, which came with these bolts that I've never seen before. I tried googling, but the best I could find is that they are called "flush anchor bolts" without any specifics on how to install them. Any help or links would be appreciated. The bolt

  • 1
    They are for cement/concrete. You drill a hole of the right size using a masonry bit, put the anchor in the hole, and tighten up the nut. What is the material the wall is made out of? Wood studs need a different screw/bolt type.
    – crip659
    Commented Apr 15 at 17:19
  • It's a limestone wall with an outer layer of cement, I was expecting plastic expansion bolts, since those come with any furniture that needs hanging, but I'm guessing these are more reliable
    – seMikel
    Commented Apr 15 at 18:51

1 Answer 1


That's a sleeve anchor for concrete or heavy stone. It should not be used for other applications due to the intense expansion force involved and the design intent. It requires a hole of a specific size (usually stamped on the hardware, but basically the outside diameter of the part) and of slightly more depth that its insertion length. When tightened, the wedge at the bottom is driven into the sleeve, forcing it outward and creating grip.

  1. Drill a hole of the correct diameter and adequate depth using a rotary hammer or hammer drill and suitable bit.

  2. With the nut on the threads and past the end, drive the anchor into the hole until the sleeve is just flush. It should not take much force at all. This gives you the ability to pull the part out of the hole if needed. If you're having trouble, run the drill again and clean out any dust or debris.

  3. Remove the nut and washer. This serves to fix any damaged threads.

  4. Install your furniture.

  5. Reinstall the washer and nut, then snug it down.

Caveat: The sleeve needs to be kept pressed into the hole during tightening. If your furniture has mounting holes larger than the sleeve, such that the sleeve could pull through the furniture, add a second washer behind the furniture of the same size as is provided with the anchor.

  • Thanks, had to google some of the terms, but it seems clear now, wouldn't the sleeve need to stick out a little to expand as the nut is being tightened? Also when you say "for concrete" I'm assuming limestone should be fine, right?
    – seMikel
    Commented Apr 15 at 18:56
  • I don't understand your reasoning. The sleeve needs to be retained by something at the surface so it doesn't slide out when the bolt is pulling against it. There's nothing to stick out. It depends on the integrity of the limestone. There's a lot of expansion force applied. I have no idea what structure we're talking about.
    – isherwood
    Commented Apr 15 at 19:12
  • Maybe I misunderstood, looking at the anchor I imagine the nut as it tightens would push at the sleeve so that the end of it inside the wall would expand, in which case there needs to be some length of the sleeve to push at, otherwise the washer would hit the wall.
    – seMikel
    Commented Apr 15 at 19:24
  • The nut pulls the stud. It doesn't push the sleeve. The sleeve is completely buried in the wall. It's only if the sleeve starts to slip outward that the washer becomes critical. It may not.
    – isherwood
    Commented Apr 15 at 19:36

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