Used Equipment

Tips on Air Cylinders

What do you need to know to select the right air cylinder from the huge variety available in the industrial marketplace? Here is the answer.

How much force do you need to move the object you wish to move?

You’ll need to know the weight of the object. Consider what the object being moved is sliding and know that this friction is adding to the load.

Oversize the required force of the cylinder by 25% to take into account friction of the rod and piston seals within the air cylinder itself, and also allowing a safety margin as it relates to the expected load the cylinder will see.

Know your available air pressure (example: 90 PSI) and multiply that times the surface area of the piston inside the cylinder to get the theoretical output force of the cylinder.

If you multiply 3.14 x the radius – in inches -squared this equals the surface area of the piston in square inches.

Since cylinders only come in certain bore sizes, default to the standard cylinder bore that’s the next size up if none are exactly the bore diameter calculated. Note that the size of the outside of the cylinder on some types has no real bearing on what the piston diameter inside the cylinder is.

How far do you wish to move the object?

If you wish to move the object five inches, it’s logical to think that the cylinder piston / rod travel needs to be five inches. It could be that simple. It might not be. Take into account the size of the object that’s to be moved to be sure that the object itself doesn’t impact on the cylinder rod cap on retract.

You may wish to consider a cylinder with a longer stroke than required so that the piston of the cylinder can be stopped inside the barrel by having the object itself stop the movement. This stops the piston from “bottoming out” on either cap of the cylinder itself. Depending on the cycle speed, this may increase cylinder life.

Take into account how you are connecting your load to the cylinder rod. If using a clevis of some sort, take that dimension into account.
Regardless of what is attached to the end of the rod, the rod itself can only move the distance that the piston inside the cylinder can move. That’s all the stroke distance you have to work with.

How will you attach your object to the cylinder rod?

Careful, if you screw the object onto the rod thread directly. Make sure that the “load” and the rod are aligned.

A rod clevis is a “sloppy” connector that screws onto the end of the rod thread. Bolt the other half to your object, and the two halves are connected in the center via a cotter pin of sorts.

This “sloppy” type of connector forgives some misalignment between the rod travel and the object movement for if the object is too far off the axis of the rod, you will very quickly encounter problems with the air cylinder.

There are alignment couplers commercially available that will further absorb misalignment between load and rod. For extreme misalignment cases, the load can be installed on rods external to the cylinder, removing almost all side-load from the rod itself.

Note that there are standards in rod thread size which change depending on the bore size of the cylinder.

Further, the rods themselves can be modified to reduce the size of the thread, to change the type of thread, to make the rod end a female thread, or to replace the standard rod thread with a stud that can, if the stud breaks, be removed and replaced at minimal cost to parts and downtime.

How will you attach the cylinder to your machine?

Depending on the type and size of cylinder there are many options of unique and  standard mounts.

Most cylinders come with integral mounting of some sort, whether it’s a rod-cap thread, a rear-cap thread, a rear tang for a clevis mount, threaded holes into which bolts can be turned, front or rear flanges, trunnion mounts…and so on. It depends on the type of cylinder.

Remember, if the load that’s being moved is not aligned with the rod travel, you will have problems. Therefore, the type and location of load will help determine the type of cylinder mount too.

What type of cylinder?

Some choices are:

·    repairable air cylinders or “throw-away” non-repairable types
·    NFPA cylinders (north American standard) or ISO cylinders (European standard)
·    aluminum, steel, stainless steel, composite construction
·    steel rod, stainless steel rod, chromed rod

Usually, as the bore size of the cylinder gets larger the style opted for is a repairable type, as more money will be spent on acquiring the cylinder therefore the cost for repair becomes a smaller percentage of the overall cost. It’s hard to get excited about trying to fix a $80.00 cylinder when the parts cost $30.00 and it will take a worker two hours to fix it. On the other hand, if the cylinder costs $500.00 – a different story.

As the bore size of the cylinder changes, so too will the rod diameter and rod threads, and the port sizes.

NFPA cylinders are imperial dimensions and imperial threads, ISO cylinders are metric dimensions and threads.

You need to consider the conditions into which the cylinder will be installed to determine if you need specialty materials in their construction. Also, specialty seals may be required in corrosive, low or high heat environments.

Cushions?

As referred to earlier, if you can avoid stopping the cylinder by having the piston “bottom out” inside the barrel, good. This will increase cylinder life. If this isn’t practical, your cylinder caps can usually have cushion vents installed which, when adjusted, trap and slow the exhaust of a small amount of air from inside the cylinder as the piston reaches end of stroke. This provides a cushion to lessen the impact of the piston to the end cap.

Where is it?

If the application requires knowledge of load position, proximity sensing devices can usually be added to the barrel of the cylinder. They will “make” when a magnet on the piston inside the cylinder passes them. Since the distance from the magnet to end-of-rod is known, this will locate the load.

There are a variety of position sensing options for cylinders including reed switches, hall effect switches, linear potentiometers,  or you can elect to sense the position of the load itself by using a barrel proximity switch mounted so that the switch “makes” as the load itself arrives.

If you need position sensing, make sure the cylinder you choose has that capability both in terms of magnets on the piston, and external mounts for the switch itself.

And there you have it – six steps to finding the right cylinder. Good luck in your hunt.

About the Author

Visit the Knowledge Bin website to learn about how to get rid of chipmunks and pictures of cows

.

SMC PNEUMATICS CDP-4A CYLINDER CLEVIS PIN *NIB* $1.00

Keystone HO #0004 Small Brake Cylinder w/Clevis $1.75

SUZUKI LTR450 06-09 REAR BRAKE MASTER CYLINDER CLEVIS LT R450 LTR 450 $2.00

Bimba Air Cylinder Piston Rod Clevis Pin Mount D-166-1 NEW $2.75

1″ HYDRAULIC CYLINDER CLEVIS PINS 2 Pins $3.80

KZ1000 Z1 KZ900 Rear Master Cylinder Rod w/Clevis Drag Bike Kawasaki $4.99

Bimba, D-231-3, D2313, Clevis Cylinder Bracket, Rod Clevis $5.99

64-72 Disc / Drum Brake Master Cylinder Booster Clevis $6.00

SMC CQ-D050 CQD050 CLEVIS, REAR, DOUBLE CQ2 COMPACT CYLINDER 50MM CQ2 KIT/ACCESS $7.00

HYDRAULIC CYLINDER ROD CLEVIS ENDS WITH HEAVY DUTY 1″ PINS / (1) PAIR $7.95

V-Factor Rear Master Cylinder Plunger/Clevis For Harley FL Models OEM# 41770-58 $7.99

2PK CLEVIS PIN (CYLINDER)(OEM Part # NotAvailable) HAP015 $9.50

CKD M1-FA-20 Pneumatic Air Cylinder Clevis ! NEW ! $9.99

Boss Snowplow RT3 Lift Cylinder Clevis Pin Kit MSC05674 New in Package OEM Part $9.99

Boss Snowplow RT3 Lift Cylinder Clevis Pin Kit MSC05674 $9.99

Numatics Clevis for Cylinder SC4/080 (NIB) $10.00

BIMBA MC-50 CLEVIS MOUNT 2-1/2 FOR PNEUMATIC AIR CYLINDER NEW $11.50

CLEVIS AND PIN MASTER CYLINDER Dune Buggy VW Baja $11.99

1″ HYDRAULIC CYLINDER CLEVIS PINS / 5 PINS $12.00

Bosch 1 827 001 290 Parts 1827001290 Cylinder Rod Clevis 1-1/8″ 15/32″ 1-17/32″ $12.00

Rexroth Clevis Kit Task Master Pneumatic Cylinder $12.00

Mannesmann Rexroth Cylinder Clevis End 3/4″ Dia. of Pin $12.50

11045 03A0015605 Cylinder Clevis $13.10

BIMBA PNEUMATIC CYLINDER CLEVIS ATTACHMENT # D-231-1 , LOT OF 2 $13.95

Bimba 1-1/16″ Bore Air Cylinder 095-P And D-166-1 Piston Rod Clevis Pin Mount $14.00

Mannesmann Rexroth P-057236-K0000 L1100 Clevis Kit Master Cylinder P057236K0000 $14.95

SMC cylinder double acting, dual clevis NCDJ2D10-150-B $14.99

Ingersoll-Rand Aro Cylinder Rod Clevis Mounting 20541 $15.00

CKD M1-00-30 ROD EYE / CLEVIS for PNEUMATIC AIR CYLINDER – NEW $15.00

CKD M1-FA-30 ROD EYE / CLEVIS for PNEUMATIC AIR CYLINDER – NEW $15.00

CKD M1-Y-30 ROD EYE / CLEVIS for PNEUMATIC AIR CYLINDER – NEW $15.00

CKD S1-Y-100-XP5 ROD EYE / CLEVIS for PNEUMATIC AIR CYLINDER – NEW $15.00

Clevis for Hydraulic cylinder $15.00

Clippard 9CD4 Clevis Mount Pneumatic Cylinder $16.50

JOHN DEEERE HYDRAULIC CYLINDER END CLEVIS R82290 DR $17.00

1815 NEW Hyster 362037 Cylinder Clevis $19.06

Ingersoll-Rand Aro Cylinder Rod Clevis Mounting 20544 $19.99

NEW FESTO LBG-100 CLEVIS FOOT MOUNTING KIT FOR COMPACT CYLINDER SERIES 46333 $19.99

Ingersoll-Rand Aro Air Cylinder Rod Clevis Bracket Mounting Kit 20521 $19.99

Hydro Line DEB-05-KA2 Male Cylinder Clevis ! NEW ! $19.99

J.B. WEBB 10780 NEW CYLINDER ROD CLEVIS 10780 $20.00

HydroLine Female Clevis for Cylinder BDC-05 (NEW) $20.00

AIR CYLINDER, TIEROD, 1 1/2″ BORE X 1″ STROKE, CLEVIS $21.99

Master Cylinder Clevis for Harley Servicar / Servi-car $23.09

clippard rod end clevis RC-2081 RC 2081 cadillac gage v150S new cylinder 3/8 $23.50

CLEVIS, ROD AIR CYLINDER ALLENAIR 445 RC $25.00

SUZUKI LTR450 REAR BRAKE MASTER CYLINDER W/YOSHIMURA CLEVIS LT R450 LTR 450 $25.00

HydroLine Female Clevis & Pin for Cylinder BDC-07 (NEW) $25.00

NEW SPEEDAIRE Clevis Cylinder Mounting Bracket 6X479 $25.00

CAP104970 UPS DELIVERY TRUCK AIR CYLINDER CLEVIS $28.90

55-57 Chevy Pass. Car Master Cylinder Push Rod and Clevis Nice* $29.55

Paughco Rear Master Cylinder Plunger/Clevis For Harley FXST & FXWG $29.99

AIR CYLINDER, 50MM BORE X 50MM STROKE, CLEVIS MOUNT $29.99

NEW BOSCH 1-827-001-291 REAR CLEVIS KIT FOR PRA / PRB PROFILE CYLINDERS 55310 $29.99

Paughco Rear Master Cylinder Plunger/Clevis For Harley FXST & FXWG $30.73

Ingersoll-Rand Aro MP1 Fixed Clevis Mounting Kit for Air Cylinder 115478 $32.00

Brass Air Pneumatic Cylinder 2.475″x 12″ x 3/4″ w/ 3/4″ Thread & Clevis $34.00

Clippard C1 Pneumatic Air Cylinder UDR-80-1-SP Clevis Spring End $34.99

TRACTOR PART NO: 1D1014-12. Clevis ROD END, Hydraulic CYLINDER $37.58

TRACTOR PART NO: 1D1503-3. Base, Hydraulic CYLINDER Clevis $37.97

NUMATICS P1CN-01EC-AAA4 PNEUMATIC CYLINDER 3″ BORE 1-1/4″ STROKE FIXED CLEVIS MT $38.39

SMC cylinder air 20mm, 50mm stroke dbl act, with clevis CDG1DN20-50 $38.50

ROYAL, AIR CYLINDER, TIE ROD, 5″ BORE X 2″ STROKE, 250 PSI, CLEVIS MOUNT $39.99

Ingersoll-Rand Aro Air Cylinder Clevis Bracket 40038 $40.00

Ingersoll-Rand Aro MP2 Detachable Clevis Mounting Kit for Air Cylinder 115290 $40.00

SMC ROUND BODY AIR CYLINDER DOUBLE CLEVIS 2 1/2″ BORE $40.14

32351 New-No Box, 40-05 Cylinder Clevis, 1/2-20″ Threads 3/4″ OD, 3-3/4″ Long $42.00

New Motion Controls K Series 2″ Bore 2″ Stroke Clevis Mount Hydraulic Cylinder $42.49

Norgren Magnetic 2 x 1″ NFPA Air Cylinder w/ Clevis $42.50

ARO 119627 Fixed Clevis Bracket 4″ Cylinder Mounting Kit $42.50

TRACTOR PART NO: 1D1505-3. Base, Hydraulic CYLINDER Clevis $43.83

Parker Cylinder Rod Clevis 50944 $46.74

Suzuki RMZ250 Rear Brake Master Cylinder Asm. w/ Clevis 450 RMX RMZ 250 07-09 $47.67

Ingersoll-Rand Aro 115480 MP1 Fixed Clevis Mounting Kit for Air Cylinder $48.00

Clevis Stop Cylinder Clevis Stop NEW STEEL with COPPER Sleaves 3/4” Diameter $49.99

Hydraulic Cylinder 4″ Bore 7 1/2″ Stroke Clevis Rod End $49.99

Parker 2-1/2″ Bore 4″Stroke Clevis Mount Air Cylinder 7/8-14 Thread on 1″ Rod $49.99

PR-73-51 NEW CYLINDER ROD CLEVIS WITH NYLON BUSHINGS PR7351 $50.00

Schrader Bellows CLEVIS MT PNEU Cylinder R$231 $53.89

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2″ bore x 4″ stroke, clevis ends $54.00

New Parker 0509460000 Cylinder Rod Clevis 1.50-12 w/0683720000 1-3/4″ Pivot Pin! $54.99

Air Cylinder 1-1/2″ Bore, 4-1/4″ Stroke, Dbl Acting, 1/2″ Rod Dia, Clevis Mount $55.00

SMC NCDQ2B25-45D 1″ x 1-3/4″ UNF 145psi Double Acting/Clevis AA Air Cylinder $57.66

2″ Bore, 4″ Stroke, Welded Cylinder – Clevis $59.21

SMC, AIR CYLINDER, 80 MM BORE X 150 MM STROKE, WITH ROD LOCK, REAR CLEVIS $59.99

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2″ bore x 8″ stroke, clevis ends $60.00

2″ Bore, 6″ Stroke, Welded Cylinder – Clevis $62.36

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2 1/2″ bore x 4″ stroke, clevis ends $63.00

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2 1/2″ bore x 6″ stroke, clevis ends $63.00

NEW PARKER LOW PROFILE COMPACT PNEUMATIC CYLINDER P1M025BDCY4H10 CLEVIS $64.99

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2 1/2″ bore x 8″ stroke, clevis ends $65.00

Parker Cylinder Rod Clevis BDC-13M $66.00

2″ Bore, 10″ Stroke, Welded Cylinder – Clevis $68.60

Anker Holton 1/2 x 2 x 5/8 Clevis Hydraulic Cylinder $69.00

SHRADER BELLOWS 0692050000 NFPA Hydraulic Cylinder Mounting Clevis Bracket G9 $69.95

2″ Bore, 12″ Stroke, Welded Cylinder – Clevis $71.97

Hydraulic Cylinder, Tie Rod, 2500 PSI, 3″ bore x 6″ stroke, clevis ends $72.00

Hydraulic Cylinder, Tie Rod, 2500 PSI, 2″ bore x 14″ stroke, clevis ends $74.00

Pneumax 0002038048B Air Cylinder with Clevis/Yoke $74.99

NEW – 15.75″ Cylinder with Clevis $75.00