Zavtilo home Parts counter / Austin
Section 05 / Anchors

Wedge anchors for concrete hold when the hole is right.

Wedge anchors for concrete in zinc and 304 stainless from 1/4 to 3/4 in, and flush drop-in anchors for overhead rod with the setting tool that matches them. Most anchor failures we hear about start at the drill, so the drill size and embedment table is on this page, not buried in a box insert.

Zinc and 304 stainless 1/4 to 3/4 in Boxes of 25 or 50
BIN 05-A / WEDGESet test block
Zinc wedge anchors beside a drilled concrete block, one partly set
The expansion clip is the whole anchor. It only grips if the hole matches the anchor diameter and is blown clean.
Line 05.1 / Wedge anchorsPrice basis
Material
Carbon steel, zinc plated; 304 stainless
Diameter
1/4, 3/8, 1/2, 5/8, 3/4 in
Drill bit
Equal to anchor diameter, ANSI carbide
Set by
Installation torque on the nut
Supplied
Anchor, hex nut and flat washer assembled
Price basis
Per box of 25 or 50 by diameter

Box size depends on diameter: 3/4 in comes in 25, smaller sizes in 50. Pricing is confirmed in the written reply.

Line 05.1 / Wedge anchors

Wedge anchors, zinc and 304 stainless

A wedge anchor is a threaded stud with a tapered end and a steel clip. You drill a hole the same diameter as the anchor, drive it in, and torque the nut. The torque pulls the cone up into the clip and the clip bites the wall of the hole. It is the standard choice for base plates, machine feet, racking and handrail posts in solid concrete.

Zinc is for dry interior slabs. Outdoors, in a wash bay, near a cooling tower or anywhere chlorides get at it, take 304 stainless. Zinc plate on an anchor is a few tenths of a thousandth thick and it does not last a Texas summer of sprinkler water on a patio slab.

What we will not do is sell wedge anchors for hollow block or brick. The clip has nothing to expand against and the anchor spins in the hole. If that is your substrate, say so in the inquiry and the reply will cover what we can source.

Send a parts list
BIN 05-B / DROP-INWith setting tool
Drop-in concrete anchors with a steel setting tool
One tool per anchor size. The shoulder on the tool stops the plug at the right depth.
Line 05.2 / Drop-in anchors

Drop-in anchors and the tool that sets them

A drop-in is a short internally threaded steel shell with a plug inside. You drill, drop the shell in flush, and drive the plug down with the setting tool until the tool's shoulder meets the shell lip. The shell flares and locks. Then you thread in all-thread or a bolt. It is how overhead pipe hangers, cable tray and duct get hung from a deck.

The anchor size is the internal thread, not the outside. A 3/8 drop-in takes a 1/2 in drill bit. Get that wrong on a ladder and the whole row of holes is scrap. The table below has every pairing.

We sell the setting tool per each, and we strongly suggest buying it with the first box. A punch or a bolt head does not stop at the right depth, and an under-set drop-in looks fine until the rod is loaded.

Material
Carbon steel, zinc plated
Internal thread
1/4-20, 3/8-16, 1/2-13, 5/8-11
Profile
Flush, lipped shell
Use
Overhead rod hangers, flush fixings
Price basis
Per box of 50; setting tool per each

Rod to hang from them is cut to length on the threaded rod page.

Drill size and embedment table

MOD 05 / Setting data
Wedge anchors, solid normal-weight concrete. Check the manufacturer's sheet for your exact part before loading.
AnchorDrill bitMin embedmentMin hole depthTypical install torqueWrench
1/4 in1/4 in1-1/8 in1-3/8 in4 ft-lb7/16 in
3/8 in3/8 in1-1/2 in1-3/4 in25 ft-lb9/16 in
1/2 in1/2 in2-1/4 in2-1/2 in50 ft-lb3/4 in
5/8 in5/8 in2-3/4 in3 in85 ft-lb15/16 in
3/4 in3/4 in3-1/4 in3-1/2 in175 ft-lb1-1/8 in
Drop-in anchors. Size is the internal thread; the drill is larger.
Internal threadDrill bitHole depthSetting tool
1/4-203/8 in1 in1/4 tool
3/8-161/2 in1-9/16 in3/8 tool
1/2-135/8 in2 in1/2 tool
5/8-117/8 in2-1/2 in5/8 tool

Figures are standard values used across common brands. They are a guide for ordering and drilling, not a load rating. Load values come from the manufacturer's published data for the exact anchor, and we send that sheet on request.

The setting mistakes we hear about every week

MOD 05 / Failure modes
Fault 01

Dust left in the hole

Drilling dust packs under the clip and the anchor sets on powder. Blow, brush, blow. Two passes of each on 1/2 in and up.

Fault 02

Worn drill bit

A carbide bit that has drilled a hundred holes cuts undersize, the anchor will not drive, and someone hammers the threads flat. Change the bit.

Fault 03

Too close to the edge

Keep wedge anchors at least five diameters from a slab edge and ten from each other. Closer than that and the concrete cones out before the anchor gives.

Fault 04

Torqued with an impact gun

Impact torque is a guess. Set with a torque wrench to the number in the table, then stop.

Fault 05

Drop-in set with a punch

The plug stops short, the shell never fully flares, and the hanger lets go months later. Use the matched tool.

How an anchor order goes

Send the diameter, the length, zinc or stainless, and the count. If you also tell us the slab thickness and what is being fixed, the reply flags a length that will not reach minimum embedment through your base plate.

  1. Your list

    Day 0

    Diameter, length, finish and count. Add plate thickness if you know it.

  2. Written reply

    Stock and price

    Boxes on the shelf, anything short, and whether the length reaches embedment through your fixture.

  3. Picked and labelled

    At the counter

    Boxes stay sealed. Part boxes go in labelled bags with size, finish and count. Setting tools ride in the same bag.

Anchor questions, answered

Not in hollow block or brick. A wedge anchor expands against solid concrete. In hollow masonry the clip has nothing to bite on, and the anchor spins. Ask us for a sleeve anchor quote instead.

Yes. The tool is sized to drive the internal plug to the correct depth. A punch or a bolt leaves the plug short and the anchor never fully expands.

Zinc for dry interior work only. Anything outdoors, in a wash-down area or in treated lumber contact gets 304 stainless.

No. We are a parts counter, not an engineer of record. Load values depend on concrete strength, cracking, spacing and edge distance, and they come from the manufacturer's data and your designer. We will forward the published sheet for the exact anchor we supply.

Drill once.Order the right box.

Diameter, length, finish and count. The written reply covers stock, box quantities and the setting tool if you need one.

Send a parts list
04Threaded rod cut to length 03Nuts and washers 10Base plate blanks 00Whole catalogue