DISTRIBUTOR-FIRST SUPPLY PARTNER · SINCE 1999 Live · Pneumatic Automation System
SPC Company
Pneumatic Automation / Actuation / Cylinders / Rodless Cylinder
Layer 04 · Actuation Industry Leader · SMC
01What it is

Rodless Cylinder

A rodless cylinder is a linear actuator with no extending piston rod — an external carriage rides along the outside of the barrel, coupled to the internal piston either magnetically or through a sealed stainless band. Because nothing projects beyond the barrel ends, the cylinder occupies roughly its own body length rather than nearly double that length when a conventional rod is fully extended. That saves close to one full stroke of installed space, making rodless the answer for long-stroke linear motion in space-constrained installs: gantry transfer systems, pick-and-place axes, packaging-line transfer slides, material-handling shuttles. The carriage carries the working load directly, so carriage load capacity and moment loading — not just rod force — are central sizing parameters.

Compare tiers ↓ How to sell this ↓ Request a quote →
Real-world reference Representative rodless cylinder
Rodless Cylinder — representative product photo
02Why it's needed

Why this matters.

Tips and pointers on when rodless is the right long-stroke cylinder — and when a rod-style or electric actuator is the better call. Scroll the strip →

01 · Key point
Installed length equals stroke.

An external carriage rides the outside of the barrel — no extending rod. 1m of stroke = 1m of installed length, not 2m. The only practical answer above 600mm and the dominant family for gantry transfers, pick-and-place axes, and long packaging-line slides.

02 · Key point
Magnetic = leak-tight clean-room.

Magnetically coupled rodless uses a magnet ring through the sealed barrel wall — no slot, no leak path. The right answer for clean-room, food-contact, vacuum-chamber, or semiconductor wafer handling where any air escape to atmosphere is unacceptable.

03 · Key point
Band-coupled = higher force.

Sealed-band rodless uses a stainless band that lifts at the carriage and re-seals behind — direct mechanical coupling, no breakaway risk, higher force than magnetic. Small inherent leak rate; correct for general industrial gantries and material handling.

04 · Pro tip
Size the carriage, not just the bore.

Force-bore math drives propulsion; carriage load + moment loading (torque around each axis) + acceleration drive bearing geometry. Pick: basic + external guide, slide-bearing (light), ball-bearing (medium), or high-rigidity guided (heavy). Strokes over 1.5m need mid-span barrel support — quote the brackets.

05 · Where not to use
Stroke under 300mm.

Rodless is over-spec'd, harder to switch-integrate, and more expensive than rod-style at short stroke. → Switch to ISO 15552 under 300mm; ISO is rebuildable, has cleaner sensor integration, and costs less.

06 · Where not to use
Magnetic past breakaway force.

Load exceeding the magnetic coupling's rated breakaway force decouples the carriage from the piston mid-stroke — drops the load. → Switch to band-coupled for higher force, or upsize the bore to push breakaway above the worst-case dynamic load.

07 · Where not to use
Precise mid-stroke positioning.

Rodless does fast end-to-end pneumatic motion — not programmable position profiles, not closed-loop servo control. → Switch to an electric actuator when the application needs mid-stroke positioning, repeatable position recipes, or servo feedback.

03Key selection criteria

What we need to spec it right.

From the machine spec sheet → to the part number. Answer what you know — leave the rest blank — and send.

01 · Input
Pull from the load calculation; add 25-50% safety factor. Force = pressure × piston area drives propulsion bore.
Push · Pull · Both (double-acting)
02 · Input
Confirm the regulator setting at the machine drop. Most plants run 80-90 PSI.
60 PSI · 80 PSI · 100 PSI · 120 PSI
03 · Input
Derived from required force ÷ operating pressure. Rodless bores roughly follow rod-cylinder ranges.
16 mm · 25 mm · 32 mm · 40 mm · 50 mm · 63 mm · 80 mm · 100 mm
04 · Input
Rodless is chosen specifically for long strokes — usually the only practical answer over 600mm.
300-600 mm · 600-1500 mm · 1500-3000 mm (mid-span support req'd) · >3000 mm (specify)
05 · Input
The carriage carries the load directly. Total weight + offset from centerline + max acceleration drive guidance type more than bore does.
Total load (lbs / kg) · Offset from centerline (in / mm) · Max accel (g)
06 · Input
Magnetic is leak-tight (clean-room, food, vacuum) but force-limited at breakaway. Band is higher force with small inherent leak rate.
Magnetic (leak-tight) · Band-coupled (high force)
07 · Input
Sized from carriage load and moment, not bore alone.
Basic (pair with external guide) · Slide-bearing (light) · Ball-bearing (medium) · High-rigidity guided (heavy)
08 · Input
Strokes over 1.5-2 m need mid-span barrel support to prevent sag — quote brackets on the same line.
None (stroke <1.5 m) · 1 mid-span bracket · 2+ brackets (long stroke)
09 · Input
High speed + heavy carriage exceeds built-in cushion limits.
<500 mm/sec (cushion sufficient) · 500-1000 mm/sec (external shocks) · >1000 mm/sec (stroke adjusters + shocks)
10 · Input
Groove-mount or rail-mount switches matched to the series. Quote extend + retract + any mid-stroke positions.
None · 2 (extend + retract) · 3+ (multi-position transfer)
11 · Input
Clean-room / food / vacuum mandates magnetic coupling. Washdown needs IP67 switches and sealed cable entry.
Standard industrial · Washdown · Clean-room / food · Vacuum chamber
12 · Input
Premium tier earns out on production-rate. Carriage bearing service life ≈ 50-100M cycles on integrated guides.
Single-shift · Two-shift production · 24/7 continuous
13 · Input
Number of cylinders for this configuration. Need different bores, strokes, or coupling types? Add a separate quote line per variant.
1 cylinder · 2-4 (gantry / multi-axis) · 5+ (production fleet)

Need different sizes, colors, or quantities? Fill the form, add to quote, then fill again — each click is one quote line.

04Choose your solution tier  ·  core differentiator

Whatever your lever — spec, value, or price — SPC has the right brand.

Most distributors sell one brand per product type. SPC's 60-brand portfolio means every Product Type page surfaces three real options matched to how your customer is buying today. Pick the tier; the quote desk handles the cross-reference.

01 Industry Leader 1 brand
SMC
MY1 mechanically jointed rodless cylinder series
View brand →
05How to sell this  ·  distributor talk track

The tier conversation closes the deal. The cross-reference catalog wins the next one.

Rodless is the long-stroke answer. Whenever the customer says I need 600mm or more of travel, rodless is the cylinder family. The sizing isn't just force-bore math — carriage load and moment matter as much as the pneumatic spec.
The SPC difference · how distributors actually buy

The 30-second positioning

Rodless is an engineered sale with a longer technical conversation than rod-style cylinders. Start with stroke length (which is what brought the customer to rodless), then expand to carriage load profile.

The five-piece structural conversation:
1. Confirm stroke length — rodless above ~300mm, only practical answer above ~600mm.
2. Capture carriage load profile — total load weight, attachment offset from centerline (creates moment), max acceleration (drives dynamic moment), cycle rate (drives thermal duty).
3. Compute force-bore at operating pressure with safety factor.
4. Choose coupling type — magnetic (leak-tight, force-limited) for clean-room/food/vacuum; band-coupled (higher force, small leak) for everything else.
5. Specify guidance — integrated slide-bearing (light loads), integrated ball-bearing (medium loads), or external linear guide pairing (heavy loads / high moments). Strokes over 1.5-2m also need mid-span barrel support.

Tier: Industry Leader tier — global premium, the OEM-default for new automation. Full coupling matrix (magnetic + band-coupled), full guidance matrix, full accessory ecosystem. Primary call and SPC's lead. Emerging tier — value-tier exists at materially lower price but narrower variant coverage. Economical tier — skip on rodless. Quality variance is severe (carriage bearing wear, band-seal aging, coupling loss); not a category where saving 30% is worth mid-stroke decoupling on a moving load.

Customer cue → talk move

"Need long-stroke, 1 meter or more"
Rodless, immediately. Rod-style at 1m needs 2m installed length
"Gantry transfer, two axes, long travel"
Industry Leader tier with integrated ball-bearing linear guide on both axes
"Clean-room or food-contact, can't leak air"
Magnetically coupled (MY-1M). Verify breakaway force vs. worst-case load
"Carriage decoupled mid-stroke on magnetic"
Load exceeds breakaway force — switch to band-coupled or upsize
"Heavy load, side load, high moment"
External linear guide PAIR with rodless. Cylinder = propulsion only
"Replace existing rodless"
Match existing spec (same tier); confirm coupling type, guide type, bore/stroke
"Sticking mid-stroke"
Carriage bearing wear (most common) or band-seal damage on band-coupled
Request a quote → Back to tier compare ↑
06Where it's used

Industries served.

Each industry below uses this product across the listed areas. Open an industry to see how it fits the rest of its system.

Food & Beverage Processing Food & Beverage Processing →
  • Gantry transfer systems and X-Y-Z slides
  • Food-processing and washdown transfer systems
Pharmaceutical, Medical Device & Laboratory Pharmaceutical, Medical Device & Laboratory →
  • Clean-room and pharmaceutical equipment
Packaging & Printing Packaging & Printing →
  • Packaging machine longitudinal axes
Metalworking & Fabrication Metalworking & Fabrication →
  • Robotic and CNC auxiliary axes
Material Handling & Conveyors Material Handling & Conveyors →
  • Material-handling slides and shuttles

Also applies to The largest install application · Long-travel pick-and-place axes · Magnetically coupled · Vacuum-environment automation

09Install · 7 critical steps

The things that matter on the first install.

Step 01
Capture the carriage load profile before specifying
Total load weight, attachment point offset from carriage centerline, max acceleration / deceleration, cycle rate. These four numbers determine whether you're in basic-type, integrated-slide-bearing, integrated-ball-bearing, high-rigidity, or external-guide-paired territory. Get them all before quoting; under-specified rodless fails at the carriage bearings or magnetic coupling.
Step 02
Calculate force-bore math at operating pressure
Required push force ÷ (operating pressure × piston area) = bore. Add 25-50% safety factor. Carriage propulsion force is the bore-area force; carriage load capacity is a separate spec set by the bearing geometry.
Step 03
Choose magnetic vs band coupling
Magnetic = leak-tight (mandatory for clean-room, food, vacuum) but force-limited (decouples at breakaway). Band-coupled = higher force, small inherent leak rate, acceptable for general industrial. Match to the leak-tightness requirement and force budget.
Step 04
Choose guidance type
Basic (pair with external guide). Integrated slide-bearing (PTFE-bushing carriage — light loads). Integrated ball-bearing (medium loads, precise motion). High-rigidity guided (heavy loads, precision). External guide paired (heavy loads or high moments).
Step 05
Specify mid-span barrel support on long strokes
Strokes over 1.5-2 meters need mid-span support to prevent barrel sag. Spec the support brackets on the same order; they're cylinder-bore-specific and customers often forget them.
Step 06
Set end-of-stroke control with stroke adjusters or external shock absorbers
Built-in air cushions on heavier loads or higher cycle rates aren't enough. Stroke adjusters set a hard mechanical end-of-stroke and engage external heavy-duty adjustable shock absorbers sized to carriage load × velocity.
Step 07
Install switches with the carriage cycled at operating speed
Magnetic switches mount in the barrel's switch grooves (slightly different geometry from rod cylinders). Set with the carriage cycling at production speed — static positioning misses the trigger point. Stock spare switches at install — most common rodless failure item.
10Troubleshoot · top failures

Most returns trace to one of these causes.

Symptom
Most likely cause
Fix
Carriage stops short of full stroke or won't move under load
Air supply or piston seal issue, carriage bearing binding from contamination, mid-span barrel sag deflecting carriage path, or — on magnetic — load exceeded breakaway and carriage decoupled from piston.
Check supply pressure first. For bearing binding, clean surfaces, inspect for damage. For magnetic decoupling, the application is over-rated for the cylinder — reduce load, switch to band-coupled, or upsize. For mid-span sag, add or relocate barrel supports.
Air leaking continuously from the barrel slot (band-coupled)
Band seal worn, damaged, or warped after years of cycling. The stainless band is a wear item that fails over millions of cycles. Less commonly: debris in slot, or carriage misalignment lifting the band.
Replace the band — Industry Leader tier rodless lines supply replacement-band service kits. Inspect slot for debris before installing new band. If band fails again within a year, suspect alignment — re-shim the carriage.
Carriage motion rough or sticky over part of the stroke
Carriage bearings worn or contaminated (after years of high-cycle service), barrel surface scored, or — on integrated-guide types — guide rail damaged.
Inspect bearings; replace if worn (typically 50-100M cycle service life on premium lines). Clean and re-lubricate. For damaged barrel or rail, the cylinder is at end of life — replacement.
Position switches triggering inconsistently
Switches drifted in grooves (vibration), wiring damage (cable management failure on moving installs), or — rarely — piston magnet weakening.
Re-position switches with carriage cycling at production speed. Replace switches with damaged cabling. Magnet replacement is rare; typically a full cylinder replacement.
End-of-stroke hammer despite cushion adjustment
Cushion exhausted by carriage load × velocity (cushion has rated limits), cushion seal worn, or stroke adjuster missing on heavy-load application.
Install external shock absorbers (heavy-duty adjustable) at both stroke ends — built-in cushion alone isn't enough on heavier loads.
Slow acceleration or labored motion under load
Cylinder undersized for moment loading even though force-bore math looks correct (customer underestimated load profile), carriage bearings overloaded creating drag, or supply pressure/flow inadequate.
Recompute carriage load and moment. If rated bearing capacity is exceeded, the install needs a larger cylinder, a higher-guidance variant, or external linear guides. Verify supply pressure under load.

Get the right rodless cylinder on quote in 24 hours.

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