A rebar coupler joins two reinforcement bars end to end. Many coupler systems need a thread on the bar end, and that thread has to be right on every single bar, because the joint carries the full load of the bar.
Why the thread is rolled
A thread can be cut or rolled. Cutting removes material. Rolling presses the steel into shape without removing any, which leaves the thread root stronger. In fatigue testing on bolt steel, rolled threads reached more than twice the fatigue strength of cut threads. Rolling is also faster and leaves no chips.
What the machine has to handle
The bar arrives long, heavy and ribbed, and it has to be cut, faced and threaded to a repeatable length without an operator handling it between steps.
The AKEA GEW 103 is built for that duty:
- Rebar threading from M12 to M56
- Thread lengths up to 500 mm
- Part lengths from 200 mm to 12,000 mm
Where the work moves beyond rebar into tube and bar, the GA Series covers chamfering, peeling and thread rolling in one pass:
- Diameters from ø12 to ø100 mm
- Threads from M12 to M100
- Part lengths from 300 mm to 6,000 mm
- 50 to 500 parts per hour
- 1 to 3 spindles and 1 to 3 clamping vices
The same thread on every bar
A coupler system is only as good as its worst thread. When chamfering, peeling and thread rolling run in one automated sequence, every bar end gets the same treatment, with no variation from one operator to the next.
Talk to us
AKEA Automation has built special purpose machines for metal processing in the steel and aluminium industries for more than 30 years, everything in-house from development and design through programming, test and service. For rebar and fastener threading projects, contact Kasper Bilstrup.
Frequently asked questions
Can you thread rebar?
Yes. Rebar is threaded by cold rolling a parallel thread onto the bar end after the bar is cut to length and faced. The rib pattern is removed in the threaded section during the peeling or rolling operation.
What is a rebar coupler?
A mechanical splice that joins two reinforcement bars end to end in place of a lap splice. Requirements and test methods are set in ISO 15835.
What are the main rebar coupler types?
Parallel threaded couplers using a thread rolled onto the bar end, couplers using pressed muffs, and swaged or grouted sleeve systems. Threaded couplers are the ones that involve a threading operation on the bar.
Is a rolled thread stronger than a cut thread?
In fatigue, yes. In testing on bolt steel, rolled threads reached more than twice the fatigue strength of cut threads.
What size rebar can be threaded on one machine?
The AKEA GEW 103 covers M12 to M56 with thread lengths to 500 mm and bar lengths from 200 mm to 12,000 mm.