For columns, walls, beam sides and pile cages
Vertical Rebar Spacers
Maintain side or radial concrete cover by keeping the steel at the required distance from shuttering or the pile-bore face. Choose the spacer after checking the drawing and steel arrangement.
01 · Side cover
Side cover has to stay correct during site work
In a column, wall or beam side, the steel has to remain at the distance from shuttering shown on the structural drawing. In a pile, the cage has to remain at the specified radial distance from the bore. The spacer does not decide this cover; it maintains the position already required by design.
This is why a vertical spacer has two jobs. It must establish the required distance and it must remain attached to the reinforcement while the cage, shuttering and concrete work are handled.
02 · Retention
A vertical spacer cannot behave like a loose block
A slab cover block can support steel from below. A vertical spacer is different: gravity does not hold it in the useful position. It has to remain attached while the cage is moved, shuttering is closed, workers handle reinforcement and concrete is placed.
If a spacer rotates, slides or comes off, the cage can move closer to one face and the actual cover can become less than intended. This is why fixing strength and resistance to dislodgement matter in addition to the nominal spacer dimension.
03 · Products
Four products, different fixing geometry
CLB-40, SL-2540, SL-40 and PS-50 all help maintain vertical or radial cover, but they are not interchangeable. Their locking geometry, cover behaviour and application are different.
- CLB-40: CROSSLOCK self-locking cover block positioned at the ring/main-bar crossing.
- SL-2540: ring-mounted Spiderlock with two cover orientations, 25 mm and 40 mm.
- SL-40: dedicated 40 mm ring-mounted spacer with push-fit double locking.
- PS-50: dedicated wheel-type spacer for radial cover in pile cages.
The fixing point and appropriate reinforcement arrangement matter as much as the specified cover.
04 · Ring-mounted spacers
SL-2540 and SL-40 are different Spiderlock designs
Both SL-2540 and SL-40 are ring-mounted Spiderlock spacers, but they solve the job differently. SL-2540 is a multi-cover spacer providing 25 mm and 40 mm orientations. SL-40 is a dedicated 40 mm double-lock spacer designed for easy insertion, stronger retention and stable cover even if it rotates around the steel.
Because Spiderlock fixes to the ring, the compatibility value to check is Compatible Ring Diameter. The main longitudinal bar diameter is not the fit dimension for SL-2540 or SL-40.
05 · Dual cover
SL-2540: 25 mm / 40 mm from one spacer
SL-2540 provides two cover options in one spacer. Rotate the fitted spacer so the required cover face is towards the shuttering.
- Confirm the required cover on the structural drawing.
- Check the selected product’s compatible ring diameter.
- After engagement, orient the required cover face towards the shuttering.
06 · Dedicated 40 mm
SL-40: easier to insert, deliberately harder to pull out
SL-40 uses a push-fit double-lock: press the spacer onto the compatible ring until both locking points engage.
The double-lock design is intended to resist accidental dislodgement during normal cage and shuttering handling. Use the product only with a compatible ring and verify the final position.
07 · Applications
Where Spiderlock can be used
- Columns: support the steel cage before closing shuttering and maintain the specified cover.
- Beam sides: ensure side reinforcement remains at the required cover when the cage is installed.
- RCC walls: maintain steel position near both faces where required by the drawings.
- Pile cages: support radial position using a product specifically suitable for a lowered cage and the bore conditions.
08 · Select a product
Choose the spacer after the cover is known
Start with the required cover and application. For Spiderlock and PS-50, check Compatible Ring Diameter. CLB-40 is different because it locks at the crossing, so both ring and main-bar geometry matter.
CLB-40
Crossing-lock column/beam-side block
Designed for suitable column and beam-side reinforcement crossings. Engagement is at a main-bar and ring crossing; check both bars and required cover.
SL-2540
Spiderlock dual-cover spacer
A ring-mounted Spiderlock option with 25 mm and 40 mm cover orientations. Confirm ring compatibility and orient it as required.
SL-40
Spiderlock double-lock spacer
Dedicated 40 mm ring-mounted spacer with a push-fit double lock. Verify both retention points are fully seated on a compatible ring.
PS-50
Pile Cage Spacer Wheel
A separately designed rounded wheel for maintaining radial cover in pile cages. Confirm required cover, cage ring diameter, quantity and availability directly with CROSSLOCK.
Check the listed cover, bar compatibility and Pieces / Packet before ordering. Ask CROSSLOCK if a required value is not shown.
09 · Pile cage
PS-50 is made for pile-cage conditions
A pile cage is lowered into a bore, so its spacer has to maintain cover under contact with soil or mud rather than against normal shuttering. This is why PS-50 uses a different wheel geometry.
Its outer side is deliberately rounded. The broad rounded profile is intended to avoid digging or piercing into surrounding mud or soil while the cage is lowered.
PS-50 clips to the pile-cage ring, so ring diameter is the important fit dimension. Its push-fit locking geometry is designed for easy installation with secure retention after engagement.
For PS-50 availability and fit, share your pile-cage ring diameter, required radial cover and project details with CROSSLOCK.
10 · Quantity planning
Plan PS-50 quantity by cage length and levels
Plan pile-cage spacers from cage length, pile diameter, ring spacing and the specified radial cover. The number and vertical levels must follow the approved pile-cage design and method statement.
Larger pile diameters, unusual cages or project specifications can require a different number at each level. Follow the project requirement where it differs.
11 · Installation
Fix the spacer before shuttering or cage lowering
- Confirm the structural drawing, required side or radial cover and cage bar/ring details.
- Choose a spacer made for that application. CLB-40 locks at a crossing; Spiderlock products mount to rings.
- Fully engage each spacer at the correct location without damaging the reinforcement or product.
- Place enough supports around the cage and along its height to avoid displacement.
- Inspect retention and orientation before shuttering, handling or lowering the cage. Replace loose or damaged spacers.
12 · Comparison
What should a good vertical spacer do?
A suitable vertical spacer must maintain the specified cover and remain attached when reinforcement is moved, shuttering is closed or a cage is lowered. Check fit, geometry, orientation, load and resistance to dislodgement. Do not extrapolate one product’s test result to another.
13 · References
Codes & Technical References
This page explains product use in practical site language. Structural drawings, project specifications and the responsible engineer remain controlling.
14 · FAQs
Common questions
Is Spiderlock a separate brand?
No. CROSSLOCK is the umbrella brand. Spiderlock names the SL-series vertical spacer family under CROSSLOCK.
Why is PS-50 not called Spiderlock?
PS-50 is designed specifically for pile cages and uses its own rounded wheel geometry. It belongs under Vertical Rebar Spacers but remains a separate Pile Cage Spacer Wheel category.
Which bar diameter matters for Spiderlock and PS-50?
Compatible Ring Diameter. These products fix to the ring, so the main longitudinal bar diameter is not the fit dimension. Confirm the ring fit for the selected product.
Does SL-2540 have the same double lock as SL-40?
No. SL-2540 provides two cover orientations from a ring-mounted spacer. SL-40 is a dedicated 40 mm double-lock design. Verify application and product fit before use.
Can CLB-40 also be called a vertical spacer?
Yes, by application. CLB-40 remains a Self-Locking Cover Block by product geometry, but in suitable columns and beam sides it performs the job of a Vertical Rebar Spacer.
How many PS-50 wheels should be used?
Follow the approved pile-cage drawing, spacer-ring diameter and cage lowering method. Quantity must be selected for the actual cage dimensions and required cover.
Does the website decide concrete cover?
No. Required concrete cover comes from the structural drawing, applicable code and project specification. The website helps select a product after that requirement is known.
Technical support
Ask CROSSLOCK about your column, wall or pile cage
Share the member and project drawing, cover requirement, cage diameter, ring/stirrup diameter and photographs of the steel arrangement.