SELECTION

Which Rotary Actuator Do I Need? Match the Torque Class First

Five numbers decide the unit: rated driving torque, rotation angle, mounting interface, output shaft and valve configuration. Torque picks the size class; the other four decide whether that size will bolt on and hold. Below is the same order we work in, followed by the torque classes our six series cover next to the models from other makes that turn up in the same enquiries.

Last reviewed: October 2026

The five checks, in order

Working in this order stops the common mistake: buying on torque alone and finding the mounting pattern is 12 mm out.

Rated driving torque at your working pressure

Torque is quoted at a stated pressure — 210 bar for most helical actuators, 250 bar for some makes. Compare at the pressure your machine actually runs, not at the catalogue maximum.

Rotation angle

90°, 180°, 270° and 360° are separate builds, not adjustments. A 180° unit will not swing 360° because the port timing inside the housing is different.

Mounting interface

Foot, front flange, rear flange and valve-mount bodies do not interchange. Bolt pattern, pilot diameter and the distance from mounting face to shaft end are the three numbers that decide whether it fits.

Output shaft

Single key, double key, splined and flange shafts are all standard across the range. Shaft diameter and keyway position must match the arm or gear you are driving.

Valve and port configuration

Integral counterbalance, dual pilot check, or no valve at all. If the unit is holding a load with the engine off, the valve block matters as much as the torque rating.

Send the tag details and we run these five checks against our range and answer with the build that suits — usually within one working day.

Send your details

TORQUE CLASSES

56 torque classes, four makes side by side

Each row is one HM size with its rated driving torque. The four columns on the right list the models from other makes that come up in the same enquiries — comparable references, not validated substitutions. 54 of the 56 classes have at least one published reference.

Codes starting with I- or M- are the same housing with a different valve block. A dash means we hold no reference for that class.

HM model	Driving torque	Helac	HKS	Moveco	Sungji
HMR1 — flange-mount, 200–76,000 Nm, 15 sizes
HMR1-020	200 Nm	—	DA-H 40, I-DA-H 40	—	—
HMR1-035	340 Nm	—	DA-H 50, I-DA-H 50	—	—
HMR1-065	650 Nm	—	DA-H 63, I-DA-H 63	—	—
HMR1-135	1,350 Nm	—	DA-H 80, I-DA-H 80	—	—
HMR1-250	2,500 Nm	—	DA-H 100, I-DA-H 100	—	—
HMR1-500	5,100 Nm	—	DA-H 125, I-DA-H 125	—	—
HMR1-700	7,100 Nm	—	DA-H 140, I-DA-H 140	—	—
HMR1-1100	11,300 Nm	—	DA-H 160, I-DA-H 160	—	—
HMR1-1600	16,200 Nm	—	DA-H 180, I-DA-H 180	—	—
HMR1-2200	22,300 Nm	—	DA-H 200, I-DA-H 200	—	—
HMR1-3200	32,000 Nm	—	DA-H 225, I-DA-H 225	—	—
HMR1-3900	38,920 Nm	—	DA-H 225S	—	—
HMR1-4400	44,000 Nm	—	DA-H 250	—	—
HMR1-6000	60,800 Nm	—	DA-H 280	—	—
HMR1-7600	76,000 Nm	—	DA-H 300	—	—
HMR2 — foot-mount, 508–5,870 Nm, 7 sizes
HMR2-050	508 Nm	L20-4.5	M-DA-H-F7 70	RP17	SRB-080
HMR2-095	960 Nm	L20-8.2	M-DA-H-F7 85	RP24	SRB-090
HMR2-180	1,690 Nm	L20-15	M-DA-H-F7 120	RP33	SRB-115
HMR2-280	2,830 Nm	L20-25	M-DA-H-F7 125	RP40	SRB-140
HMR2-300	3,150 Nm	L20-25	M-DA-H-F7 125	RP40	SRB-140
HMR2-450	4,400 Nm	L20-39	M-DA-H-F7 145	RP46	SRB-160
HMR2-580	5,870 Nm	—	—	—	—
HMR3 — compact front-flange, 190–2,825 Nm, 6 sizes
HMR3-020	190 Nm	—	M-DA-H 50	—	SRA-080
HMR3-030	340 Nm	L10-3.0	M-DA-H 60	—	SRA-090
HMR3-060	620 Nm	L10-5.5	—	—	—
HMR3-100	1,075 Nm	L10-9.5	M-DA-H 80	—	SRA-140
HMR3-160	1,695 Nm	L10-15	M-DA-H 90	—	SRA-160
HMR3-280	2,825 Nm	L10-25	M-DA-H 100	—	—
HMR4 — heavy-duty, 1,920–83,600 Nm, 14 sizes
HMR4-200	1,920 Nm	L30-17	F10 115, F5 115	RR34	SRC-115
HMR4-280	2,820 Nm	L30-25	F10 125, F5 125	RR40	SRC-125
HMR4-300	3,100 Nm	L30-25	F10 125, F5 125	RR40	SRC-125
HMR4-470	4,750 Nm	L30-42	F10 150, F5 150	RR46	SRC-150
HMR4-500	5,100 Nm	L30-42	F10 150, F5 150	RR46	SRC-150
HMR4-750	7,340 Nm	L30-65	F10 175, F5 175	RR52	SRC-180
HMR4-1000	10,700 Nm	L30-95	F10 200, F5 200	—	—
HMR4-1150	11,500 Nm	L30-95	F10 200, F5 200	—	—
HMR4-1400	14,100 Nm	L30-125	F10 220, F5 220	RR58, RR61	—
HMR4-1800	18,600 Nm	L30-165	F10 245, F5 245	RR66	—
HMR4-2500	24,300 Nm	L30-215	F10 265, F5 265	RR72	—
HMR4-2850	28,500 Nm	—	—	—	—
HMR4-4200	42,900 Nm	—	F10 265S, F5 265S	RR78	—
HMR4-8300	83,600 Nm	—	F5 350, F10 350	—	—
HMR5 — valve-mount, 125–32,000 Nm, 9 sizes
HMR5-012	125 Nm	—	—	RL14	—
HMR5-025	250 Nm	—	—	RL16	—
HMR5-050	500 Nm	—	—	RL26	—
HMR5-100	1,000 Nm	—	—	RL36	—
HMR5-200	2,000 Nm	—	—	RL44	—
HMR5-400	4,000 Nm	—	—	RL52	—
HMR5-800	8,000 Nm	—	—	RL60	—
HMR5-1600	16,000 Nm	—	—	RL67	—
HMR5-3200	32,000 Nm	—	—	RL86	—
HMR6 — through-shaft straddle, 1,800–6,780 Nm, 5 sizes
HMR6-180	1,800 Nm	—	—	—	SRS-090
HMR6-280	2,830 Nm	T20-25	—	—	SRS-115
HMR6-300	3,050 Nm	T30-27	—	—	SRS-115
HMR6-500	5,090 Nm	T20-45	—	—	—
HMR6-680	6,780 Nm	T20-60	—	—	SRS-150

Comparable performance based on rated torque class for engineering comparison. The mounting interface must be confirmed by our engineering team before quotation.

Where the numbers mislead

Rated torque is not holding torque

The published figure is driving torque at a stated pressure. Holding capacity with the valve closed is a separate characteristic of the valve block, and it is what decides whether a raised boom creeps down overnight.

Two models in one torque class can differ by 30%

A torque class groups models that customers treat as interchangeable. It is not a claim that the ratings are identical — always read the reference model’s own datasheet before assuming the numbers line up.

The tag on the machine is often not the catalogue code

OEMs order modified builds: different shaft, different ports, sometimes a different rotation. A tag reading L30-65 does not tell you the whole build; the suffix on the tag does.

A bigger actuator is not automatically safer

Oversizing adds weight on the arm, changes the swing speed at the same flow, and can overload the bracket the actuator bolts to. Match the class first, then look one size up only if the duty cycle demands it.

Common questions

How do I find out which rotary actuator I need?

Start with the rated driving torque your load needs at your working pressure, then the rotation angle, then the mounting interface, then the shaft, then the valve. Torque decides the size class; the other four decide whether that size will physically fit and hold.

Can I use a model from another make in the same torque class?

Not without checking the other four dimensions. A model in the same torque class is a comparable reference — the mounting pattern, shaft, rotation angle and valve ports still have to be compared against your unit before anything is quoted.

What if I only have the OEM part number and no model code?

Send the part number, the machine make and model, and a photo of the actuator tag. We work back from the OEM number and the measured mounting pattern to the size class, and confirm before quoting.

Do you publish torque ratings for the models from other makes?

No. The table below groups models by the torque class customers put them in. For the reference model’s own rating, use the manufacturer’s datasheet — we quote ratings for HM builds only.

SELECTION HELP

Send the Tag Details and We Size It

Model code or OEM part number, the machine it is on, and the rotation angle if you know it. We run the five checks and come back with the build that suits — usually within one working day.

Or email directly: hm@hmhydraulics.com