Gardner Bender Big Ben (Aluminum hand bender): radius, deduct and gain
The Gardner Bender Big Ben (Aluminum hand bender) is a hand bender for EMT, rigid (RMC), and IMC, 1/2" to 1". These are the numbers BendMate uses for each of its shoes.
Part numbers: 960, 961, 962 (heads); 960H, 961H, 962H (with handle)
Specs by shoe
| Size | Centerline radius | Deduct | Gain | Notes |
|---|---|---|---|---|
| 1/2" EMT | 4 1/16" | 5" | 2 7/16" | Gain worked out from the radius. 960 head. Gardner Bender prints a bend radius of 3.69; it uses "bend radius" for the inside of the bend, so this is 3.69 + OD/2. |
| 3/4" EMT | 5 3/16" | 6" | 3 1/8" | Gain worked out from the radius. 961 head. Gardner Bender prints a bend radius of 4.74; it uses "bend radius" for the inside of the bend, so this is 4.74 + OD/2. |
| 1/2" RMC | 5 3/16" | 6" | 3 1/16" | Gain worked out from the radius. 961 head (3/4 EMT groove). Gardner Bender prints a bend radius of 4.74; it uses "bend radius" for the inside of the bend, so this is 4.74 + OD/2. Deduct from its rigid/IMC column. |
| 1/2" IMC | 5 1/8" | 6" | 3" | Gain worked out from the radius. 961 head (3/4 EMT groove). Gardner Bender prints a bend radius of 4.74; it uses "bend radius" for the inside of the bend, so this is 4.74 + OD/2. Deduct from its rigid/IMC column. |
| 1" EMT | 6 3/8" | 8" | 3 15/16" | Gain worked out from the radius. 962 head. Gardner Bender prints a bend radius of 5.81; it uses "bend radius" for the inside of the bend, so this is 5.81 + OD/2. |
| 3/4" RMC | 6 5/16" | 8" | 3 3/4" | Gain worked out from the radius. 962 head (1 EMT groove). Gardner Bender prints a bend radius of 5.81; it uses "bend radius" for the inside of the bend, so this is 5.81 + OD/2. Deduct from its rigid/IMC column. |
| 3/4" IMC | 6 5/16" | 8" | 3 3/4" | Gain worked out from the radius. 962 head (1 EMT groove). Gardner Bender prints a bend radius of 5.81; it uses "bend radius" for the inside of the bend, so this is 5.81 + OD/2. Deduct from its rigid/IMC column. |
Marks on the shoe
- 1ArrowLine your marks up here. This is the arrow the app’s marks are for.Printed as “Arrow”
- 245° center notchThe center of a 45° bend: line up a mark placed on a bend’s center, like a three-point saddle’s middle bend.Printed as “Rim Notch”
- 3StarThe back of a 90: for a 90 measured to its back, like the second of two back-to-back 90s.Printed as “Star”
- 4Sight marksSight past these to read the angle when bending on the floor.Printed as “Angle Arrows”
- 5Angle linesThe conduit lines up with each one as the bend reaches that angle, bending in the air.Printed as “Degree Scales”
The angle is read on the lines and marks on the head.
Where the numbers come from
Bend with the Gardner Bender Big Ben (Aluminum hand bender) in BendMate
Choose it in the app and every mark comes from these numbers. Edit any of them to match your own bender.
Common questions
What is the deduct for 1/2" EMT on the Gardner Bender Big Ben (Aluminum hand bender)?
5". Subtract it from the stub length to find where to mark a 90. The shoe’s centerline radius is 4 1/16" and its back-of-90 gain is 2 7/16".
What is the deduct for 3/4" EMT on the Gardner Bender Big Ben (Aluminum hand bender)?
6". Subtract it from the stub length to find where to mark a 90. The shoe’s centerline radius is 5 3/16" and its back-of-90 gain is 3 1/8".
What is the deduct for 1" EMT on the Gardner Bender Big Ben (Aluminum hand bender)?
8". Subtract it from the stub length to find where to mark a 90. The shoe’s centerline radius is 6 3/8" and its back-of-90 gain is 3 15/16".
What is the deduct for 1/2" RMC on the Gardner Bender Big Ben (Aluminum hand bender)?
6". Subtract it from the stub length to find where to mark a 90. The shoe’s centerline radius is 5 3/16" and its back-of-90 gain is 3 1/16".
Brand and model names only identify the bender. BendMate isn’t affiliated with or endorsed by Gardner Bender. Check the numbers against the markings on your own bender.