Collection: KELM Series KI ISO 15552 Pneumatic Cylinders

Technical information & FAQs

KELM KI ISO 15552 Pneumatic Cylinders

KELM Series KI pneumatic cylinders are magnetic double-acting ISO 15552 profile actuators built for industrial machinery, OEM equipment and replacement applications. The Gen 2 range combines an extruded aluminium profile barrel with an AISI 304 stainless-steel piston rod, integrated reed-switch slots and adjustable pneumatic cushioning at the end of the stroke.

KI covers bore sizes from 32 to 125 mm and includes an extensive selection of stroke lengths, making it suitable for everything from short clamping and positioning movements to long-travel handling, transfer and machine automation.

If you already know the KELM manufacturer part number, use the complete KI code to select the exact pneumatic cylinder. Alternatively, browse all KELM pneumatic cylinders, compare the wider ISO 15552 pneumatic cylinder range, or narrow the catalogue using the bore links below.

Stainless-Steel Piston Rod as Standard

One of the defining characteristics of the KELM KI range is its piston-rod specification. Current KELM technical documentation specifies an AISI 304 stainless-steel piston rod as standard across the Gen 2 ISO 15552 range.

This gives KI a useful material advantage for general industrial environments while retaining the conventional aluminium-profile construction associated with ISO 15552 pneumatic cylinders.

KELM KI Technical Specification

Manufacturer	KELM
Series	KI
Generation	Gen 2
Product Category	Profile pneumatic cylinders
Dimensional Standard	ISO 15552
Operation	Double acting
Bore Sizes	32, 40, 50, 63, 80, 100 and 125 mm
Position Detection	Magnetic piston
Sensor Mounting	Reed-switch slots integrated into the extruded profile
Cushioning	Adjustable pneumatic cushioning
Barrel Material	Extruded aluminium
Piston Rod	AISI 304 stainless steel
Pneumatic Ports	BSPP parallel female
Working Pressure	1 to 10 bar
Working Temperature	-20°C to +80°C
Recommended Medium	Clean compressed air, filtered to 40 µm

KI Bore Sizes from 32 to 125 mm

The KELM KI platform covers seven standard industrial bore sizes, allowing the same ISO 15552 actuator family to be used across a wide range of force requirements.

32 mm bore pneumatic cylinders — compact ISO 15552 machine movement and positioning.
40 mm bore pneumatic cylinders — general automation, clamping and fixture duties.
50 mm bore pneumatic cylinders — increased force for handling and production machinery.
63 mm bore pneumatic cylinders — medium-to-high force industrial actuation.
80 mm bore pneumatic cylinders — larger machine and transfer applications.
100 mm bore pneumatic cylinders — high-force ISO 15552 movement.
125 mm bore pneumatic cylinders — the largest standard KI bore for substantial industrial actuation.

KELM KI Ports and Piston-Rod Threads

The pneumatic connection and piston-rod thread increase with bore size, so the full KI manufacturer part number should be retained when replacing an existing pneumatic cylinder.

Bore	BSPP Port	Piston-Rod Thread
32 mm	1/8"	M10 × 1.25
40 mm	1/4"	M12 × 1.25
50 mm	1/4"	M16 × 1.5
63 mm	3/8"	M16 × 1.5
80 mm	3/8"	M20 × 1.5
100 mm	1/2"	M20 × 1.5
125 mm	1/2"	M27 × 2

Long-Stroke Pneumatic Cylinder Options

KELM KI is not restricted to conventional short and medium strokes. The Cylinder Warehouse catalogue includes long-travel KI pneumatic cylinders such as 40 mm bore × 800 mm stroke, 63 mm bore × 800 mm stroke and 80 mm bore × 900 mm stroke.

The wider published KI range extends to 1000 mm stroke on selected bore sizes, giving the series useful capability for gates, transfer mechanisms, handling equipment and machinery requiring substantial linear travel.

For very long strokes, the piston-rod loading and buckling conditions of the actual application should be checked rather than selecting the pneumatic cylinder solely from bore and stroke.

Adjustable Pneumatic Cushioning

KELM KI pneumatic cylinders include adjustable cushioning. As the piston approaches the end of its stroke, the cushioning arrangement allows the final deceleration to be tuned to suit the moving mass and operating speed.

This can help reduce end-of-stroke impact, noise and mechanical stress, particularly on larger-bore pneumatic cylinders or long-stroke applications where the moving assembly carries greater kinetic energy.

Magnetic Piston and Integrated Reed-Switch Slots

The standard KI range is magnetic, allowing compatible cylinder switches to provide non-contact piston-position feedback.

The extruded aluminium barrel incorporates reed-switch slots, allowing sensors to sit neatly within the profile rather than requiring a separate external mounting arrangement.

This makes KI particularly useful on automated machinery where the PLC needs confirmation that the pneumatic cylinder has completed its extension or retraction before the next part of the machine cycle begins.

Examples from the KELM KI Range

KELM MPN	Bore	Stroke	Port	Rod Thread
KI-32BX100-S-G	32 mm	100 mm	1/8" BSPP	M10 × 1.25
KI-40BX160-S-G	40 mm	160 mm	1/4" BSPP	M12 × 1.25
KI-50BX600-S-G	50 mm	600 mm	1/4" BSPP	M16 × 1.5
KI-63BX300-S-G	63 mm	300 mm	3/8" BSPP	M16 × 1.5
KI-80BX900-S-G	80 mm	900 mm	3/8" BSPP	M20 × 1.5
KI-100BX250-S-G	100 mm	250 mm	1/2" BSPP	M20 × 1.5
KI-125BX125-S-G	125 mm	125 mm	1/2" BSPP	M27 × 2

KELM KI for ISO 15552 Replacement

The ISO 15552 format makes KI a useful option for both new machinery and replacement applications where standardised profile-cylinder dimensions are required.

However, ISO 15552 should not be treated as the only compatibility check. Before replacing another manufacturer's pneumatic cylinder, compare the bore, stroke, overall mounting arrangement, piston-rod thread, pneumatic port, cushioning, sensing and any accessories fitted to the existing actuator.

Browse the wider ISO 15552 pneumatic cylinder range where a cross-brand comparison is required.

Why Use KELM KI Instead of a Compact Pneumatic Cylinder?

KI is designed around the conventional ISO 15552 profile-cylinder format and is particularly strong where standardised mounting, long strokes and a broad range of bore sizes are required.

If minimum overall actuator length is the primary constraint, a compact pneumatic cylinder may be more appropriate. Browse compact pneumatic cylinders or the KELM compact series where the machine has limited axial installation space.

KELM KI Selection Questions

Is KELM KI definitely ISO 15552?

Yes. KELM's current technical documentation identifies the KI Gen 2 range as ISO 15552 pneumatic cylinders.

Is KELM KI double acting?

Yes. Standard KI pneumatic cylinders are magnetic double-acting actuators.

Does KI have adjustable cushioning?

Yes. Adjustable pneumatic cushioning is standard on the published Gen 2 KI range.

What piston-rod material does KI use?

KELM specifies an AISI 304 stainless-steel piston rod as standard on its current Gen 2 ISO 15552 range.

What bore sizes are available?

The standard KI range covers 32, 40, 50, 63, 80, 100 and 125 mm bore.

Can I buy a long-stroke KELM KI pneumatic cylinder?

Yes. Cylinder Warehouse already carries numerous long-stroke KI combinations, and the wider published range includes selected configurations up to 1000 mm stroke.

Are KELM KI ports BSPP?

Yes. The current range uses BSP parallel female pneumatic connections, with port size increasing from 1/8" on 32 mm bore up to 1/2" on 100 and 125 mm bore versions.

Can KI be compared with another manufacturer's ISO 15552 pneumatic cylinder?

Yes. ISO 15552 provides a strong dimensional basis for comparison, but bore, stroke, rod thread, port, cushioning, sensing and mounting details should all be confirmed before substitution.

Where can I browse the rest of the KELM range?

Return to all KELM pneumatic cylinders or browse the complete pneumatic cylinder range.

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280 pneumatic cylinder products in this range.

KELM
KI-32X100-S-G
32mm bore x 100mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X100-S-G

£58.28 EX VAT

£69.94 INC VAT

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KELM
KI-32X50-S-G
32mm bore x 50mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X50-S-G

£69.89 EX VAT

£83.87 INC VAT

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KELM
KI-32X75-S-G
32mm bore x 75mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X75-S-G

£60.79 EX VAT

£72.95 INC VAT

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KELM
KI-40X25-S-G
40mm bore x 25mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X25-S-G

£57.15 EX VAT

£68.58 INC VAT

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KELM
KI-40X50-S-G
40mm bore x 50mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X50-S-G

£68.79 EX VAT

£82.55 INC VAT

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KELM
KI-40X75-S-G
40mm bore x 75mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X75-S-G

£58.56 EX VAT

£70.27 INC VAT

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KELM
KI-40X100-S-G
40mm bore x 100mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X100-S-G

£71.59 EX VAT

£85.91 INC VAT

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KELM
KI-32X160-S-G
32mm bore x 160mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X160-S-G

£71.59 EX VAT

£85.91 INC VAT

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KELM
KI-40X125-S-G
40mm bore x 125mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X125-S-G

£63.63 EX VAT

£76.36 INC VAT

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KELM
KI-40X200-S-G
40mm bore x 200mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X200-S-G

£84.58 EX VAT

£101.50 INC VAT

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KELM
KI-32X250-S-G
32mm bore x 250mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X250-S-G

£69.66 EX VAT

£83.59 INC VAT

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KELM
KI-50X25-S-G
50mm bore x 25mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X25-S-G

£79.48 EX VAT

£95.38 INC VAT

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KELM
KI-50X50-S-G
50mm bore x 50mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X50-S-G

£87.14 EX VAT

£104.57 INC VAT

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KELM
KI-50X75-S-G
50mm bore x 75mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X75-S-G

£84.48 EX VAT

£101.38 INC VAT

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KELM
KI-32X80-S-G
32mm bore x 80mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X80-S-G

£72.99 EX VAT

£87.59 INC VAT

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KELM
KI-50X100-S-G
50mm bore x 100mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X100-S-G

£91.31 EX VAT

£109.57 INC VAT

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KELM
KI-50X80-S-G
50mm bore x 80mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X80-S-G

£76.66 EX VAT

£91.99 INC VAT

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KELM
KI-32X125-S-G
32mm bore x 125mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X125-S-G

£76.14 EX VAT

£91.37 INC VAT

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KELM
KI-50X125-S-G
50mm bore x 125mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X125-S-G

£94.55 EX VAT

£113.46 INC VAT

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KELM
KI-32X150-S-G
32mm bore x 150mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X150-S-G

£78.68 EX VAT

£94.42 INC VAT

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KELM
KI-40X300-S-G
40mm bore x 300mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X300-S-G

£82.48 EX VAT

£98.98 INC VAT

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KELM
KI-50X175-S-G
50mm bore x 175mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X175-S-G

£82.66 EX VAT

£99.19 INC VAT

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KELM
KI-40X80-S-G
40mm bore x 80mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X80-S-G

£81.87 EX VAT

£98.24 INC VAT

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KELM
KI-50X150-S-G
50mm bore x 150mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X150-S-G

£84.43 EX VAT

£101.32 INC VAT

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KELM
KI-32X200-S-G
32mm bore x 200mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-32X200-S-G

£85.00 EX VAT

£102.00 INC VAT

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KELM
KI-63X25-S-G
63mm bore x 25mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-63X25-S-G

£94.15 EX VAT

£112.98 INC VAT

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KELM
KI-40X150-S-G
40mm bore x 150mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-40X150-S-G

£90.99 EX VAT

£109.19 INC VAT

View Details
KELM
KI-50X250-S-G
50mm bore x 250mm stroke
ISO 15552 | Profile Cylinder
Manufacturer Part Number KI-50X250-S-G

£91.12 EX VAT

£109.34 INC VAT

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