RS2H vs RSH Comparison
Size from pallet weight, transfer speed, and conveyor friction using SMC's operating range charts. In SMC's examples, a 300 kg pallet at 20 m/min (friction coefficient 0.1) calls for the RS2H 63mm bore, and a 10 kg pallet at 10 m/min (friction coefficient 0.1) falls in the RSH 20mm range.
| Specification | RS2H | RSH |
|---|
| Bore and standard stroke | 50mm: 30mm
63mm: 30mm
80mm: 40mm | 20mm: 15mm
32mm: 20mm |
| Operating range (SMC charts) | Up to 1,000 kg | Up to 80 kg |
| Weight | 1.70, 2.78, 4.96 kg | 0.41, 0.75 kg |
| Port | Rc, NPT (TN), G (TF): 1/8 on 50mm, 1/4 on 63 and 80mm. Flange side or axial (A) piping. | 20mm: M5 only
32mm: Rc, NPT (TN), G (TF) 1/8 |
| Roller lever direction | Four positions in 90 degree steps | 32mm: 90 degree steps. 20mm: reversible 180 degrees. |
| Auto switches | D-M9, D-A9, D-P3DWA on three sides | D-M9 and D-Z7/Z80 (D-A9 cannot be mounted) |
| Both series | Flange mounting. Lever with built-in shock absorber, resistance set by adjustment dial. Resin (L) or carbon steel (M) roller. Double acting, double acting spring, or single acting spring extend. Built-in magnet standard. Max operating pressure 1.0 MPa, proof 1.5 MPa, -10 to 60°C (no freezing). |
Options and When to Use Them
| Code | Option | Use It When |
|---|
| D | Lock mechanism | Pallets are light enough to rebound off the shock absorber spring. |
| C | Cancel cap | Some pallets must pass. The cap holds the lever horizontal. |
| S | Lever detection switch | The PLC needs a signal that the pallet reached the stop position. An OMRON proximity switch turns on when the lever stands erect. |
Options combine in the order D, C, S, for example -DCS. With a lock mechanism, do not let a pallet strike the roller while the lever is locked, and lower the cylinder before moving pallets by hand.
Reading an RS2H or RSH Part Number
Example: RS2H80-40DM-D with an auto switch suffix such as -M9BW
| Segment | Meaning |
|---|
| RS2H80 | Series and bore. A port code can follow: TN (NPT) or TF (G); RS2H can add A for axial piping. |
| 40 | Stroke (fixed by bore) |
| D | Action: D double acting, B double acting spring type, T single acting spring extend |
| M | Roller material: L resin, M carbon steel |
| -D | Options D, C, S in that order. On RS2H, a P, Q, or R after the options sets the lever position relative to the port. |
| -M9BW | Auto switch model, lead length (none 0.5m, M 1m, L 3m, Z 5m), and S for one switch. With no switch, the cylinder still has a built-in magnet. |
Installation and Ordering Notes
- Conveyor height: set the conveyor between the upper and lower limit positions shown on SMC's dimension drawings, and allow for the 0 to +1.4mm stroke tolerance.
- Mounting from the lever side: RSH needs a 48mm hole (20mm bore) or 63mm hole (32mm bore), with a mounting base no thicker than 8mm or 9mm. RS2H mounting base thickness is limited to 10, 15, and 18mm for 50, 63, and 80mm bore.
- Shock absorber adjustment: start at the maximum resistance setting and work down until the pallet stops without impact or bounce. Recheck periodically, since resistance can change with temperature and wear.
- Environment: keep water, cutting oil, and dust off the shock absorber. RS2H offers a shock absorber with scraper (-X2541) made to order.
- Auto switches ship with the cylinder but are not assembled.
- RS2H made to order: low resistive force shock absorber for lighter loads (-X2464, 50mm only) and lock release specification (-XC102), which unlocks the lever if a pallet moves backward into it.
Maintenance Parts
Replacement shock absorbers: RS2H-R50, RS2H-R63, RS2H-R80, RSH-R20, and RSH-R32. Seal kits: RS2H50D-PS, RS2H63D-PS, RS2H80D-PS (double acting and spring type) and RS2H50T-PS, RS2H63T-PS, RS2H80T-PS (single acting); RSH20D-PS, RSH32D-PS, RSH20T-PS, and RSH32T-PS. Grease pack: GR-S-010. Find them in Stopper Cylinder Parts.
Discontinued Heavy Duty Stoppers and RS2H Replacements
| Discontinued Series | SMC Discontinued | Replacement | Notes |
|---|
| RSH 50, 63, 80mm | Aug 2005 | RS2H, same bore | Mounting interchangeable. RSH80-40TM becomes RS2H80-40TM. RSH 20 and 32mm are still current. |
| RS1H | Aug 2012 | RS2H | Same mounting pitch and height to roller center. RS2H is up to 22% lighter with a cylinder tube up to 9mm shorter. |
| RSA, RSA-X721 | Sep 2015 | RS2H-X2700, RS2H-X2701 | Made to order. Mounting interchangeable, but the cylinder tube is shorter. Contact us to confirm the full code. |
Heavy Duty Stopper Cylinder FAQ
What is the difference between SMC RS2H and RSH?
RS2H covers 50, 63, and 80mm bore for heavy pallets, with SMC operating range charts up to 1,000 kg. RSH covers 20 and 32mm bore for lighter pallets, with charts up to 80 kg. Both are flange mounted with a roller lever, a dial-adjustable built-in shock absorber, and the same lock, cancel cap, and lever detection switch options.
What replaced the SMC RS1H stopper cylinder?
SMC replaced the RS1H with the RS2H in August 2012. The RS2H keeps the same mounting pitch and height from the mounting surface to the roller center, so it drops into existing RS1H installations. It is up to 22% lighter and has a cylinder tube up to 9mm shorter.
How do you adjust the shock absorber on an RS2H or RSH?
Loosen the M4 set screw, turn the adjustment dial to match the energy of the pallet, then retighten the set screw to 1.5 N·m. SMC recommends starting at the maximum resistance and reducing it until the pallet stops without impact or bounce.
Should I choose a resin or carbon steel roller?
Both series offer a resin roller (L) or a carbon steel roller (M) in the part number. SMC provides the two materials so the roller can be matched to the application and pallet surface. If you are replacing an existing stopper, match the roller code in the old part number.
Can the lever direction be changed after installation?
Yes. Loosening the guide rod frees the lever so it can be repositioned relative to the piping port. RS2H and RSH 32mm rotate in 90 degree steps, and RSH 20mm can be reversed 180 degrees.
Need help sizing a heavy duty stopper?
Send us the pallet weight, conveyor speed, and any current part number. Automation Distribution, an authorized SMC distributor, will confirm the bore, roller, and options, or the RS2H replacement for an older stopper.
Contact Automation Distribution
