Removable bollard 90mm
Key lock · SW-RB90
from $120 per unit, ex GST & freight
Installation guide
What size core drill for a removable bollard socket?
Short answer: For the 90mm removable bollard (SW-RB90), core drill about Ø130mm for its Ø102 × 4 × 225mm socket. For the 140mm (SW-RB140), core drill about Ø220–225mm for its Ø152 × 4mm socket. Confirm the 140mm size and depth with us before you drill. The hole is bigger than the socket so the gap can be filled with non-shrink grout or concrete.
Figures: SafeWise product data. Standards are quoted as commonly cited guidance, so check the current edition. How we check.
Two numbers decide the core bit: the socket diameter and the socket length. Here they are for both SafeWise removable bollards.
Updated 28 October 2026
Sizes
Core bit and socket sizes by SKU
Two numbers decide the job: the diameter of the core bit and the length of the socket.
| SKU | Socket | Core bit | Socket depth | Cover plate |
|---|---|---|---|---|
| SW-RB90 (90mm) | Ø102 × 4mm | About Ø130mm | About 225mm | Ø187 × 6mm |
| SW-RB140 (140mm) | Ø152 × 4mm | About Ø220–225mm. Confirm with us before you drill. | Confirm with us before you drill | Ø214 × 6mm |
Each removable bollard comes with its own matched socket, so the two sizes are not interchangeable. Download the one-page core drill card (PDF) to send to your driller.
The gap
Why the hole is bigger than the socket
The core bit leaves a ring of space around the socket. That gap is deliberate. It lets you set the socket plumb, and it gets filled with non-shrink grout or concrete, which holds the socket in the slab. The grout or concrete is trowelled level with the surrounding surface and cured fully before the bollard is fitted. A hole cut close to the socket's diameter leaves no room for that fill, so work to the core sizes above, or ask us.
Depth
Hole depth and the gravel layer
Drill to the full socket length plus a little extra, so there is room for a layer of compacted gravel or road base under the socket. The gravel lets water drain, because standing water in a closed hole can rust a socket over time. For the 90mm socket that means more than 225mm of hole. For the 140mm, confirm the depth with us before you drill. Do not assume the 90mm figure.
Depth in general is a bigger question than one socket. See how deep should a bollard be set.
Before you drill
Slab thickness, reinforcement and services
The slab has to be thick enough to take the hole you are cutting, and you need to know what is in it and under it. A thin or old slab, or one over a void or soft ground, may not suit a cored socket, and an installer or engineer decides whether it does. Scan for reinforcing steel and services, and lodge a Before You Dig Australia (BYDA) enquiry before any drilling. A core bit does not stop for a conduit.
The rig
Core rigs and wet coring
Cores this size are normally cut with a rig that holds the bit square, using water to cool the bit and keep concrete dust down (wet coring). A core drilling contractor or a hire shop will choose the rig, bit and method for your slab, so that is their call, not ours. We recommend a professional core driller. SafeWise supplies product only.
Pricing a job like this? Send sizes, quantities and your postcode.
Request a quoteSummary
The steps in short
The full method, including pouring a socket into new concrete, is in how to install removable bollards.
1. Locate services
Lodge the BYDA enquiry and scan the slab.
2. Core to size and depth
About Ø130mm for the 90mm socket, about Ø220–225mm for the 140mm (confirm with us), to the socket length plus gravel.
3. Add gravel
A layer of compacted gravel or road base for drainage.
4. Seat and backfill
Set the socket plumb, backfill with non-shrink grout or concrete and trowel level.
5. Cure, then fit
Cure fully before you fit or lock the bollard. For where a socket does and does not suit, see surface-mount vs in-ground bollards.
FAQs
Core drill size questions
What size core drill for a 90mm removable bollard?
Core drill about Ø130mm for the SW-RB90 socket (Ø102 × 4mm, about 225mm long). Drill to the full socket length plus a little extra for a gravel drainage layer.
What size core drill for a 140mm removable bollard?
About Ø220–225mm for the SW-RB140 socket (Ø152 × 4mm). Please confirm the hole size and depth with us before you drill.
Why is the core hole bigger than the socket?
The gap around the socket is filled with non-shrink grout or concrete, which holds the socket in the slab, and it gives you room to set the socket plumb. The fill is trowelled level with the surface and cured fully before the bollard is fitted.
Does SafeWise core drill or install the socket?
No. SafeWise supplies product only. Use a professional core driller or concreter, and have underground services located first.
Related products
Removable bollards and storage holders
Removable bollard 140mm
Key lock · SW-RB140
from $140 per unit, ex GST & freight
Bollard storage holders
Parks a removed bollard · 90mm & 140mm
from $25 per unit, ex GST & freight
Bollards are pre-order on the next container: factory production typically takes 15–20 days, plus sea freight and customs. Storage holders are in stock now.
Need removable bollards for a job?
Tell us your quantities and delivery postcode. We will send a written quote with freight and the expected landing date.
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