Manual, electric and automatic rebar bending and cutting machines, when a cut-and-bend shop beats a site yard, BS 8666 shape codes, minimum bend radius rules, coil versus straight bar, safety and a buying checklist.
Rebar is cut and bent in one of three ways: by hand tools for small, one-off work, by electric or hydraulic bench benders and shears on site, or by automatic machines in a cut-and-bend shop working from a bar bending schedule. Whichever you choose, bends must be made round a mandrel to at least the minimum radius the design code sets, and shapes must follow the schedule. Bars for any of these routes come from steel rebar suppliers in the UAE or rebar suppliers in Saudi Arabia.
This guide is for site managers, rebar subcontractors, plant managers and buyers deciding whether to buy or rent bending and cutting machines, set up a site yard, or send schedules to a cut-and-bend shop. It covers machine types, what a bar bending schedule must contain, bend radius rules, coil versus straight bar, and safety. Bar grades, mills and certification are covered in our main guide to steel rebar grades, standards and mills in the UAE and Saudi Arabia.
Wikipedia's rebar article sums up the range: cages are fabricated on or off the project site, commonly with hydraulic benders and shears, while for small or custom work a hand rebar bender (a "hickey") is enough. Between those ends sits a wide range of machines:
| Equipment | What it does | Where it fits | What to check |
|---|---|---|---|
| Hand bender and bar cutter | Manual bending round a pin or jig; manual shear or bolt cutter for small bars | Small repairs, starter bars, one-off shapes | Consistent radius is hard to achieve; slow; operator strain |
| Electric or hydraulic bench bender | A rotating disc bends the bar round a central mandrel, with pins and stops to set angles | Site yards and small shops | Maximum bar diameter and number of bars per bend for your grade; mandrel set for each bar size |
| Electric or hydraulic bar cutter (shear) | Shears straight bars to length | Site yards and small shops | Maximum diameter for your grade; blade condition; length stops |
| Automatic stirrup bender | Straightens bar from coil, then bends and cuts links in one cycle | Cut-and-bend shops making large volumes of links | Coil size range; shapes it can program; straightness of output |
| Shear line and bending centre | Automatic cutting of stock bars to length and multi-bar bending of larger shapes | Cut-and-bend shops serving many projects | Bar range, capacity per cycle, software link to schedules, handling equipment |
| Specialist machines | Pile cage welding, mesh welding, truss girders, straightening | Precast and large fabrication plants | Whether the specification allows welding of the assemblies |
The machine families in the last three rows are how industrial suppliers organise their ranges. MEP Group, an Italian maker of rebar processing machines, for example, lists categories for stirrups, cut and shaping, cut to length, bend and shaping, straightening, pile and cage, mesh and truss girder, plus a fully automatic stock bar plant.
When comparing machines, ask each supplier to state the maximum bar diameter for the grade you actually use (B500B, Grade 60, or a high-strength bar such as a 600 MPa grade), both for a single bar and for several bars bent or cut together. A higher-strength bar needs more force, so a rating stated only as "up to X mm" is not enough to compare offers.
The choice is mostly about volume, space and control.
| Cut-and-bend shop | Site yard | |
|---|---|---|
| Inputs | Your bar bending schedules; the shop buys and stocks bar and coil | You buy straight bar (and coil, if you have a stirrup machine) and run the yard |
| Offcuts and waste | The shop can nest cuts across many jobs | Offcuts stay on your site unless you plan cutting lists carefully |
| Space and labour | Little on site; deliveries arrive bundled and tagged by bar mark | Laydown, machine area, crane or forklift access and a trained crew |
| Changes and urgent shapes | Need a revised schedule and a delivery slot | Can be made the same day |
| Quality evidence | Ask for the shop's process certification (for example CARES approval on British-standard projects) and mill traceability per bar mark | Your own inspection and records |
You can also combine the two: most shapes from a shop, and a small site bender and cutter for changes and starter bars. The scale of offcut waste when bars are cut from 12 m stock, and why scheduled weight differs from ordered weight, is worked through in our rebar weight chart.
On British-standard projects, CARES' certification scheme requires reinforcement to be cut and bent to BS 8666, and its scheme covers manufacturers, processors and suppliers, so a CARES-approved processor is one way to evidence a shop's control. Whatever the scheme, require the shop to show which mill's bars it uses and to keep the heat number on each bundle tag.
A bar bending schedule (BBS) lists, for each bar mark, the member, bar type and size, number of bars, shape code, cut length and the dimensions of each leg. BS 8666, titled "Scheduling, dimensioning, bending and cutting of steel reinforcement for concrete. Specification", is the British standard for this work; Hong Kong's concrete code lists the 2005 edition among its acceptable standards. On ACI-based projects the schedule follows US detailing practice and the project specification instead.
Some rules matter for anyone ordering from a schedule, as summarised on a published BS 8666 shape code sheet:
Bending a bar too tightly can crack the bar and crush the concrete inside the bend. Design codes therefore set a minimum internal bend radius, and the bending machine needs a mandrel (former) of the right size for each bar diameter. Hong Kong's Code of Practice for Structural Use of Concrete 2013, a freely published code in the British tradition, is a clear example:
| Bar diameter (φ) | Minimum internal bend radius for hooks and loops |
|---|---|
| 12 mm and below | 2φ |
| Above 12 mm, below 20 mm | 3φ |
| 20 mm and above | 4φ |
The same code adds conditions: these radii may be used without checking concrete bearing only where the anchorage does not need more than 4φ past the bend, the bar is not stressed beyond 4φ past the bend, or a cross bar at least as large sits inside the bend. In no case may the radius be less than twice the radius of the test bend guaranteed by the bar's manufacturer. Use the table in the code or standard your project actually names (BS 8666 and ACI 318 set their own values); the Hong Kong table shows the logic, not your project's numbers.
The code also sets workmanship rules that translate directly into machine and yard practice:
Mills prove bendability with a rebend test. Under CS2:2012, Hong Kong's bar standard, 500B and 500C bars are bent 90° round a mandrel of no more than 4d (16 mm and below) or 7d (above 16 mm), aged at 100 °C, then bent back at least 20°, on a power bending machine at around three revolutions per minute. That is a test of the steel, not a fabrication radius.
Coated bars add their own limits. Galvanised bars bent before galvanising need generous bend diameters, and bars bent after galvanising may show some flaking; epoxy-coated bars must not be cut with a flame torch, and cut ends need epoxy repair. Both are covered in our guide to GFRP, epoxy-coated and galvanised rebar.
Stirrup machines that straighten and bend bar from coil avoid offcuts on links. Gulf mills publish coil ranges: EMSTEEL (Emirates Steel Arkan) lists rebar coil from 8 to 16 mm in 2.0 ton coils; Conares lists 6 to 16 mm coils of 1.8 to 2.2 tons; Qatar Steel lists 7 to 16 mm coils of 1,050 to 1,200 kg; and Al Rajhi Steel lists coils from 6 to 16 mm. Check that the coil weight and inner diameter suit the machine's decoiler, and that your specification accepts decoiled bar for the members concerned.
Larger bars are processed from straight stock, usually 12 m. Shear lines and bending centres need feed tables, bundle handling and storage racks sized for those lengths. CRSI advises storing bars on timbers away from mud and standing water, sorted by size and length, with easy access for re-handling.
Rebar machines combine heavy rotating parts, shearing blades and long bars that swing as they bend. General machine-guarding principles apply; the US OSHA rules are a useful checklist:
On top of that, keep the bending arc clear of people, train operators on the machine's emergency stop and on setting mandrels and stops, and plan lifting of long bundles with suitable construction equipment. Follow your local occupational safety rules and the machine maker's manual.
If you would rather compare shops, machines and bar supply side by side, post your cutting and bending requirement on ListGCC with your tonnage, bar range and schedule format. For rental machines, also look at construction equipment suppliers in Saudi Arabia.
More in this series: Rebar Sizes and Bar Marks, Rebar Couplers and Mechanical Splices.
A rebar bending machine bends reinforcing bars to the shapes on a bar bending schedule. Bench machines use a rotating disc that bends the bar round a central mandrel, with pins and stops to set the angle. Automatic stirrup benders and bending centres in cut-and-bend shops do the same under program control, often straightening bar from coil first.
It depends on the design code and bar size. Hong Kong's concrete code, for example, requires an internal radius of at least 2 times the bar diameter for bars up to 12 mm, 3 times below 20 mm and 4 times at 20 mm and above, and never less than twice the manufacturer's test bend radius. Use your project's code or BS 8666 schedule values.
Shops suit large volumes: they nest cuts across many jobs, deliver bundles tagged by bar mark, and free up site space. Site bending suits changes, urgent shapes and small jobs, but needs laydown, machines and a trained crew. You can also use a shop for most shapes and keep a small site bender and cutter for changes.
It is a two-digit code in a bar bending schedule that defines the bar's shape, with the lettered leg dimensions listed alongside. Shape code 99 covers any non-standard shape and needs a dimensioned sketch. BS 8666 codes replaced the older BS 4466 codes, which use different numbers.
Only with the engineer's approval. Hong Kong's concrete code says grade 500 bars should not be bent, re-bent or straightened without approval, and that previously bent steel should be reshaped only with approval and inspected for fracture afterwards. Plan starter bars and laps so site re-bending is not needed.
CRSI advises cutting small epoxy-coated bars with bolt cutters and larger ones with a diamond-blade saw, never a flame torch, and coating cut ends with two-part epoxy patching material. Galvanised bars are repaired to ASTM A780 where the coating is damaged. Agree the method with the specification before cutting.
Featured image: Photo: Gpkp, CC BY-SA 4.0, via Wikimedia Commons
How to buy rebar in the UAE and Saudi Arabia: B500B and Grade 60 explained, UAE ECAS and Saudi Quality Mark rules, bar marks and mill certificates, the main Gulf mills, coated bars and pricing terms.
How GFRP, epoxy-coated and hot-dip galvanised rebar protect concrete from chlorides, their standards and design codes, bending, cutting and repair rules, cost drivers and what UAE and Saudi regulations cover.
Metric rebar sizes and what Gulf mills roll, ASTM bar numbers in mm, what makes a bar deformed, reading the grade from ribs and rolled marks, what a delivery certificate must contain, and what CARES means.
