Specialty Rock Anchor Accessories

Spherical Washers

These adjustable angle washers are self-aligning and provide full hex nut-bearing. They can be used with Dome Plates or with thicker standard plates with chamfered holes. Use a hardened flat washer between the nut and spherical washer.

Range of Bar Dimensions
(Dia. x H x I.D.)
UNC/ / Coil Grade 75
5/8” – 7/8”
(16 – 22 mm)
(20 mm)
2” x 1/2” x 13/16”
(51 x 13 x 21 mm)
7/8” – 1-1/8”
(22 – 29 mm)
#7 – #8
(22 – 25 mm)
2-3/4” x 1-3/16” x 1-1/8”
(70 x 30 x 29 mm)
1-1/4” – 1-1/2”
(32 – 38 mm)
#9 – #11
(28 – 35 mm)
3-5/8” x 1-3/8” x 1-5/8”
(92 x 35 x 41 mm)

Domed Plates

Domed plates allow for the optimum use of Williams spherical Washers to provide high angles of variation between the bar and the plate. Plate sizes listed below are standard. Other sizes are available.

of Rotation
Collapse Load
3/8” x 6” x 6”
(10 x 152 x 152 mm)
(38 mm)
0 – 20° 50 kips
(222 kN)
3/8” x 6” x 6”
(10 x 152 x 152 mm)
(48 mm)
0 – 20° 50 kips
(222 kN)
1/2” x 8” x 8”
(13 x 203 x 203 mm)
(73 mm)
0 – 20° 100 kips
(445 kN)


Constant Torque Nuts

These hex nuts for Grade 75 All Thread Bar have a special compressed end to allow a predictable torque resistance while torquing the nut which jams onto the outer end of a threaded anchor bar. This resistance allows the bar to be rotated by the constant torque nut to mix polyester resin or to initially set a mechanical bail anchor. After the resin sets or the bail anchor is initially set, the nut can then be torqued to forces in excess of the preset resistance which will allow the nut to break away. The nut is then run down the bar and against the plate where it is torqued up to tension the anchor to the required load for a one step installation. Some of the torque resistance will remain on the nut after the initial “break away” torque.
Constant Torque Nuts are available with UNC or All-Thread Rebar type threads. Allow 1/16” to 1/8” increase in the hex size of the drive socket tool for allowance of the compressed end of these nuts. Available for bar sizes up to #11. See your Williams representative for the size and torque requirements for this product.

Spherical Seat Constant Torque Combination Square Nut/Washer

Williams has combined the spherical seat washer with a nut to deliver a one piece fastener that will both spin the bar and then self-align as it contacts the bearing plate. This nut features a constant torque compressed ring to allow a predictable torque resistance similar to the constant torque nuts above. Some of the torque resistance will remain on the nut after the initial “break away” torque of approximately 10-20 ft./lbs. The spherical seat nut is available for the following bar sizes: #6-#8 Grade 75 All-Thread Rebar, 3/4”-1-1/8” UNC, and 3/4”-1” Coil.

Note: During installation using constant torque nuts of any type, ensure that the drill hammer is off or the steel shank in the drive steel has been shortened to eliminate any hammering in the drive steel.



Want to talk? Find your Williams Form Engineering Representative.