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Technical Specifications
Last Updated: 2026-09-13| Identity | |
| Brand |  |
| Product Number | 31055S |
| Category | Hobby |
| Performance | |
| Torque |
6.0V
20.83 oz-in
1.50 kg-cm
0.1 N-m
4.8V
16.66 oz-in
1.20 kg-cm
0.1 N-m
Average
|
| Speed |
6.0V
0.14 sec/60°
428.6 deg/s
71.4 RPM
4.8V
0.18 sec/60°
333.3 deg/s
55.6 RPM
Bottom 10%
|
| Running Current |
6.0V
180.000 A
180,000 mA
4.8V
150.000 A
150,000 mA
Bottom 10%
|
| Stall Current | ≤0.45 A≤450 mAAbove Average |
| Physical | |
| Weight | 0.28 oz8.0 gAverage |
| Dimensions |
L 0.898 in W 0.457 in H 0.945 in L 22.8 mm W 11.6 mm H 24.0 mm |
| Case Material | Plastic |
| Drivetrain | |
| Motor Type | Coreless |
| Gears | Nylon |
| Gear Spline/Teeth | 15 T estimate |
| Shaft Size | 4.0 mm |
| Rotation Mode | Positional |
| Rotation/Support | Bushing |
| Backlash | 0.500° |
| Control & Signal | |
| Modulation | Analog |
| Direction | Clockwise |
| Rotational Range | 120° |
| Mechanical Limit | 200° |
| Pulse Cycle | 20 ms |
| Pulse Width | 615-2390 µs |
| Neutral Position | 1500 µs |
| Dead Band | 5 µs |
| Refresh Rate | 50 Hz |
| Angle Sensor | Potentiometer |
| Control System | PWM |
| Programmable | No |
| Signal Voltage | 3-5V |
| Electrical & Environment | |
| Operating Voltage | 4.8–6 V |
| Power Source | Direct |
| Regulator Type | Direct |
| Temperature | -20–60 °C-4–140 °F |
| Water Rating | IP4X |
| Idle Current | 0.006 A6 mA |
| Connectivity | |
| Connector | JR (Universal) |
| Wire Length | 250 mm9.84 in |
| Origin | |
| Country of Origin | South Korea |
Disclaimer: Most data is sourced from the manufacturer. Some data is sourced from our loyal community and with the help of AI. We aim for accuracy but are not responsible for inaccurate information.
Class Comparison
| Torque | Average Stronger than 40% of 170 Analog Micro servos at 4.8V |
| Speed | Bottom 10% Faster than 4% of 170 Analog Micro servos at 4.8V |
| Weight | Average Lighter than 54% of 346 Analog Micro servos |
| Running Current | Bottom 10% Lower draw than 0% of 33 Analog Micro servos at 4.8V |
| Stall Current | Above Average Lower draw than 79% of 54 Analog Micro servos |
Performance Analysis
| Shaft Power | 0.17–0.28 W |
| Power Density | 0.709 W/in³ More power-dense than 27% of 333 Analog Micro servos |
| Torque Density | 2.0825 oz-in/g Stronger than 45% of 170 Analog Micro servos |
| Torque-to-Volume Ratio | 42.96 oz-in/in³ Denser torque than 33% of 170 Analog Micro servos |
| Speed-to-Weight | 0.69444 (1/sec·g) Faster than 21% of 170 Analog Micro servos |
| Speed-Torque Trade-off | 3.00 Better balanced than 78% of 169 Analog Micro servos |
| Current-per-Torque Ratio | 0.0270 A/oz-in More efficient than 89% of 45 Analog Micro servos |
| Idle-to-Running Current Ratio | 0.000 1st-highest idle-to-running current ratio of 23 Analog Micro servos |
| No-Load vs Stall Current Spread | 0.00 1st-highest no-load vs stall current spread of 25 Analog Micro servos |
| Torque Gain per Volt | 20.86%/V More voltage-responsive (torque) than 85% of 96 Analog Micro servos |
| Speed Gain per Volt | 23.83%/V More voltage-responsive (speed) than 93% of 96 Analog Micro servos |
| Voltage Range Width | 1.2 V Wider voltage range than 77% of 182 Analog Micro servos |
| Backlash-to-Range Ratio | 0.00417 Tighter backlash than 60% of 51 Hobby servos |
| Dead-Band-to-Pulse-Width Ratio | 0.0028 5th-highest dead-band-to-pulse-width ratio of 43 Analog Micro servos |
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Reviews (9)
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Bob
May 1, 2021Application(s): After my last review, and problems I had with these servos, I decided to test the rest of the ones I had in other airplanes. After 3 out of 4 failed in the first plane I tested, I decided to remove them from all my airplanes. You just never know when they will fail. The HS65 is much better. I have Hitec servos in other airplanes, and they are fine. These are not one of the good ones.
Comments: These servos are just to unreliable to risk an airplane.
Bob
October 6, 2020Application(s): I am not a Hitec fan, after losing a new plane to a 485 failure, but I inherited a bunch of these. Some were new, others used. Put them on a Hitec servo tester, and out of 22, 12 failed, just stopped working. Doesn’t give you a lot of confidence. Come on Hitec, what’s going on? Needless to say, I will not be using them. Just isn’t worth the chance.
Comments: Nothing in this world is perfect, but the failure rate of these is completely unacceptable.
cruisa
April 22, 2014Application(s): light 3d foamies
Comments: hay waxer maybe you should learn to keep your plane in the air. not many servoes enjoy a hard impact. These servo have always responded well used in the right way and i would recomend them to anyone.
Caspar
July 28, 2013Application(s): 3D
Comments: Sh****, and slow servos. Dont buy
waxxer
March 27, 2013Application(s): Many light foamies
Comments: Don't bother if you want to make sure your plane can withstand even the slightest of impacts--these are total junk. They will break even in a moderate crash even if the control surface survives.
They are simply whimpy---and you get no hamburger tomorrow.
Coriolis
July 10, 2012Application(s): I have used these in several small foamie 3D planes, and on the FunCub for flaps.
Comments: Out of eight HS-55 servos I had, four would get stuck intermittently, usually at bad times, with several crashes occuring. Two were new with less than six flights. I have never had any of my dozen Futaba 3114's fail. I do not recommend these servos, for any use.
UAV-flier
March 20, 2012Application(s): Everything: Multiplex Easyglider rudder, elevator, ailerons; custom 100+MPH wing elevons; 3D foamy park fliers; ...
Comments: I thought these were reliable until I put them on a servo cycler--4 of 6 servos tested get stuck at unpredictable times (4.98V cycling from 900-2100ms once per 2 seconds). Three of the offending servos was marked "07.07" and another was marked "07.08". At least one of the sketchy servos was new in box until put on the cycler. I'm now wondering if some of my crashes weren't my fault? Also, the HS-55 servos are noisier and much slower than the Futaba S3110 and S3114 servos. I too have stripped the gears on a few HS-55s during crashes, but the Futabas stripped just as easily. HS-55s can be found for $9.99 each, which isn't too bad.
Gary Parker
January 13, 2012Application(s): Park flyers
Comments: These used to be the standard park flyer servo before so many other alternatives became available. They are still pretty good servos. They are fairly strong - although they will strip if abused of course - but perhaps the key thing is that they are very reliable, they never seem to fail for no reason. There are cheaper Chinese alternatives, but those sometimes fail for no reason, which could lead to the loss of a good plane. So Hitec HS-55s are well worth considering.
wheelbarrowjack
December 25, 2011Application(s): Park jets and foamies
Comments: Good bang for the buck if you want to stay with Hitec. Very similar to the cheaper Tower Pro SG90, but much more expensive. I haven't broken one yet.