Hydraulic Crimping Tool Sizing Guide: Which Crimper for Which Cable (mm² / AWG)
How to choose a hydraulic crimping tool by cable size: a mm²-to-AWG and tonnage table, when to use a ratchet crimper instead, and a 8-point check before you buy. Written for distributors, electrical wholesalers and contractors.
Hydraulic Crimping Tool Sizing Guide: Which Crimper for Which Cable
A practical way to match a crimper to your cable size in mm² and AWG — including the tonnage you actually need, when a ratchet crimper wins, and the eight checks that prevent a failed joint.
Published 11 October 2026
Most crimping problems are not tool-quality problems — they are sizing problems. A tool bought one size too small crimps the first few joints, then starts leaving loose lugs that pass a glance and fail a pull test. A tool bought far too large is heavy, tiring to use and wastes budget on capacity nobody uses. This guide is the sizing conversation we have with distributors and contractors every week, written down so you can spec a crimper before you place an order.
Everything below is drawn from the tools we actually manufacture — the YQK/YQY hand hydraulic crimpers, the WXY split heads, and the HX copper-tube tools — so the figures are real production numbers, not round marketing figures.
Step 1: Start from the cable, not the tool
Before opening any catalogue, list two numbers: the smallest conductor you crimp regularly (often a control or earth cable) and the largest lug you crimp routinely (feeder, battery or switchgear cable). The tool you need spans that band — with margin above the top end, because the largest job you meet in the field is usually bigger than the one on your desk today.
The reason the top end matters most is force. Crimping force scales roughly with conductor cross-section, so requirement jumps steeply with cable size. A 16 mm² terminal is a light job; a 240 mm² tube terminal needs around ten tonnes applied evenly. That is why the selection table below is anchored on cross-section, not on how many dies the case holds.
Step 2: Convert mm² to AWG, then read the required force
Because specifications often come in one unit and the job in the other, keep the conversion to hand. The table below pairs the common metric sizes with their AWG equivalent, the crimping force you should look for, and the type of tool that does the job properly.
Conductor size | ≈ AWG / kcmil | Force to look for | Right tool type |
|---|---|---|---|
1.25 – 10 mm² | 16 – 8 AWG | Ratchet (mechanical) | Ratchet terminal crimper |
16 – 70 mm² | 6 – 2/0 AWG | ≈ 8 T | Hand hydraulic (small frame) |
16 – 120 mm² | 6 – 4/0 AWG | ≈ 10 T | Hand hydraulic |
16 – 240 mm² | 6 AWG – 500 kcmil | ≈ 10 T | Hand hydraulic |
10 – 300 mm² | 8 AWG – 600 kcmil | ≈ 11 – 12 T | Hand hydraulic |
16 – 400 mm² | 6 AWG – 750 kcmil | ≈ 20 T | Hand hydraulic (large frame) |
50 – 400 mm² | 1/0 AWG – 750 kcmil | ≈ 11 – 12 T (motor) | Electric hydraulic |
50 – 1000 mm² | 1/0 – 2000 kcmil | ≈ 20 T | Split hydraulic (remote head) |
Working figures from the TORCHMARK YQK / YQY / WXY / EP ranges. Treat the AWG column as an approximation — always confirm the exact terminal you use, because a lug's barrel wall thickness varies by standard.
Rule of thumb for margin Choose a tool whose top rating is at least one size above your largest routine lug. If you routinely crimp 185 mm², buy a 240 mm²-capable crimper, not a 185 mm² one. Running a tool at its maximum every shift shortens its life and leaves less room for the occasional oversized job.
Step 3: Ratchet or hydraulic? The crossover is around 10–16 mm²
Below roughly 10–16 mm², a ratchet crimper is genuinely the better tool, and not just because it costs less. The ratchet locks the handles until a full crimp is completed, so an operator physically cannot stop halfway — every joint is identical, which is exactly what a control-panel or appliance lead needs. A hydraulic tool on a 4 mm² terminal is slow, heavy and unnecessary.
Above that, the economics reverse. Once you are crimping tube terminals on feeder cable, the force needed exceeds what a hand plier can produce, and the hydraulic crimper becomes the only tool that delivers a reliable result. This is why a complete crimping range — and a well-stocked distributor's shelf — carries both: ratchet pliers for small terminals, hydraulic crimpers for large lugs.
Step 4: Hand, split or electric head?
The three hydraulic formats solve different access and volume problems:
- Hand hydraulic — pump and head in one tool, two-lever operation. The default for general contractor work from 16 to 400 mm². Nothing to connect, nothing to set up.
- Split (remote head) — the crimping head is separate from the pump, joined by a hose. This lets you position the head first, then pump, which is the only practical way to crimp inside a busbar chamber, cable trough or congested panel where a fixed tool cannot swing. Heads are available up to 1000 mm².
- Electric hydraulic — a motor-driven pump replaces the hand lever, reducing operator effort on large cross-sections and repetitive bench work. Useful where a crew crimps many joints per shift.
Step 5: The eight checks before you buy
These are the points that separate a crimper that lasts a decade from one that returns to the supplier inside a year. Run through them with any quotation:
- Range brackets your work — with margin above your largest lug.
- Force matches the largest terminal — check tonnage, not just the printed size range.
- Die set is complete and correct — matched to your terminal standard (BS, DIN, or your local profile), not a generic set.
- Head rotates or opens 180° — so the tool can reach a joint in a confined space.
- Pressure release works one-handed — a stuck hydraulic head on a live joint is a safety problem.
- Dies are hardened and replaceable — replaceable dies extend the tool's life far beyond a sealed head.
- Spares and dies are available separately — a tool you cannot buy dies for is a paperweight.
- Sample crimp confirmed — get a test crimp on your own lug before committing to the order.
What a "good" result looks like A correct crimp shows a smooth, bright hexagonal compression with no cracking at the barrel, no fins of extruded metal, and the lug fully seated before crimping. If the barrel is barrelled or split, or the conductor pulls out under load, the tool was under-powered or the die profile was wrong — not necessarily faulty.
Common sizing mistakes we see from buyers
Three recur often enough to name. First, buying on price per die and ending up with a tool whose range stops below the customer's real work. Second, mixing standards — a crimper matched to DIN tube terminals will not give a correct crimp on a BS lug, and vice versa; the die profile must follow the lug, not the tool's marketing. Third, ignoring the head format, then discovering that a fixed-handle crimper cannot reach the joints in the actual installation. Each of these is avoidable with the checklist above, and each is why we ask for the terminal standard and the largest cable size before quoting.
Building a crimping range to sell
If you are a distributor building a crimping line rather than choosing a single tool, the shape that sells is predictable: one or two ratchet crimpers for small terminals (insulated and bare), a spread of hand hydraulic crimpers covering 16–240 and 10–300 mm², one 400 mm² or split head for the heavy end, and the hydraulic accessories that pull with it — knockout punches and pipe benders. Fewer SKUs than a full tool wall, but each one answers a real job.
We build that range as one family, so a single order covers ratchet, hand hydraulic, split and copper-tube tools with matched dies and OEM branding.
Tell us your cable sizes and terminal standard Send the smallest and largest conductor you crimp, your lug standard, and hand / split / electric preference. We confirm the right model, die set and lead time.See the crimping range
Frequently asked questions
What size hydraulic crimping tool do I need for 240 mm² cable?
A hand hydraulic crimper rated 16–240 mm² with about 10 tonnes of output (for example a YQK-240A or YQY-240B) crimps a 240 mm² tube terminal in one stroke. Choose a range that sits above your largest routine lug rather than exactly on it.
How much crimping force do I need for a given cable size?
As a working guide: small terminals to about 16 mm² need a ratchet crimper; 16–70 mm² roughly 8 T; 16–240 mm² around 10 T; 10–300 mm² around 11–12 T; and 16–400 mm² about 20 T. Force scales with cross-section, so keep margin above your largest terminal.
Should I use a ratchet crimper or a hydraulic crimper?
Use a ratchet crimper for small insulated and bare terminals up to roughly 10–16 mm² — it is faster and locks until a full crimp is made. Use a hydraulic crimper above that, where a hand plier cannot generate enough even force for a reliable lug.
What is the difference between hand, split and electric hydraulic crimpers?
Hand hydraulic crimpers combine pump and head in one tool for general work. Split (remote-head) crimpers separate the head from the pump so it can be positioned in confined spaces such as busbar chambers. Electric hydraulic crimpers use a motor-driven pump to cut effort on large cross-sections and repetitive work.
Can one crimper crimp both copper and aluminium lugs?
Yes, if the die profile matches the lug. Copper and aluminium lugs use different crimp profiles, so the correct dies are supplied per tool and per standard.
Related reading
See the full tool range on our hydraulic crimping tools & cable lug crimpers page, or explore the rest of the TORCHMARK line via the pump oil can collection and the professional manual drum auger.
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