BOSS CPL-Series Locknut Pancake Hydraulic Cylinder – 60 and 100 Ton, 700 Bar

A locknut cylinder has a threaded collar that winds down onto the plunger, so once you have the load at height you can lock it mechanically and take the pressure off the oil. That matters when something has to stay up for hours or days – a machine base being shimmed, a structure being packed, a mould being held. Sixty or one hundred ton, 50 mm of stroke, in 125 or 137 mm of collapsed height. Made in Taiwan with a 30 year manufacturer warranty.

Ways to buy this cylinder:

• Two capacities off the shelf: 60 ton and 100 ton, both 50 mm stroke.
• BOSS also builds 160, 200, 260, 400 and 520 ton locknut pancakes to order. Call us for a price and lead time.
• For load holding in a taller body, the CL locknut range runs 50 to 1000 ton and is an order-in item.
• If you do not need mechanical holding, the CP low profile range is lighter and cheaper.
• For long stroke lifting, the C-Series solid cylinders go to 365 mm.

Pick your capacity

Drawings and dimensions

Factory drawings for the locknut pancake range. E is the locknut collar thread, which is the part that carries the load once you wind it down.

Full dimension table

Every letter below matches the drawing above. All dimensions in millimetres unless shown otherwise.

What is in the box

• One BOSS CPL-Series locknut pancake cylinder
• Threaded locknut collar fitted
• 3/8" NPT female oil port with dust cap fitted
• Operating and safety manual (download below)
• Pump, hose and coupler are sold separately

Specifications

How to choose

• If the load has to sit at height for any length of time, this is the right family and a plain cylinder is not.
• Size on the real load plus about 20%. Both models give the same 50 mm of stroke.
• Check your clearance against 125 or 137 mm collapsed.
• These are load return. The weight of the load pushes the plunger home, so they need a load on them to retract.
• Needing more than 100 ton, or a taller lift? Ask us about the order-in locknut range up to 1000 ton.

Technicians Advice

The locknut is the whole point, so use it properly. Lift to height, then wind the collar down by hand until it seats firmly against the cylinder head – firm, not hammered – and only then bleed the pressure back so the collar is carrying the load rather than the oil. Do not leave a gap and assume it will catch if something lets go; a collar that has 3 mm to fall before it bears will shock load the threads.

Coming down is the reverse: bring the pressure back up first to lift the load off the collar, wind the collar clear, then release. People get hurt trying to unwind a collar that is still loaded. There is an overflow port in these to stop you pushing the piston out the top, but treat it as a last resort rather than a stroke indicator. And because they are load return, a CPL with nothing on it will not retract on its own – put the load back on, or press it home, before you try to store it.

Official Datasheets

📄 BOSS CPL-Series Locknut Pancake Specifications (PDF)📄 Cylinder Operating Manual (PDF)

Complete your setup

Low Profile 5 to 150 TonC-Series Solid 5 to 100 TonDouble Acting 12 to 233 Ton

Need help choosing? Call 1300 146 737 or email sales@mhfgc.com.au – real technicians, real answers.