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Pilot Bore Sprockets – 1/2” Pitch Roller Chain Sprockets

At Bolton Engineering Products Ltd, we stock a full range of pilot bore sprockets designed for reliable, efficient power transmission in machinery, conveyors, automation systems, and chain-driven equipment.

These plain bore sprockets (Type A) have an unprepared bore and require a keyway and set screw for installation, allowing them to be fully customized to fit any shaft size and meet your specific needs.

BEP Ltd have you covered – whether it be a light-duty sprocket or an item designed for continuous use, all our parts are made from high-strength materials and custom machined to tight tolerances at very competitive prices.

What Is a Pilot Bore Sprocket?

A pilot bore sprocket is a chain sprocket supplied with a basic, oversized bore, allowing engineers or machinists to finish-machine it to the exact shaft diameter or keyway required.

These sprockets are popular in:

  • Manufacturing & processing equipment
  • Agricultural and industrial machinery
  • Conveyors and material handling systems
  • Motorcycles, bicycles & chain-driven vehicles
  • General engineering and fabrication workshops

Their flexibility makes them a go-to choice for custom drive systems and OEM applications.

Technical Specifications

Specification

Details

Product Type

Pilot Bore / Plain Bore Sprocket

Chain Pitch

1/2” Pitch (BS Standard Roller Chain)

Tooth Count Options

8T to 50T+

Material

C45 Steel / Hardened Steel

Bore Type

Pilot Bore (Machinable to Required Shaft Size)

Mounting Style

Direct Shaft, Hub, or Bushing Mount

Tooth Profile

British Standard (BS / ISO Chain)

Applications

Industrial, Agricultural, Conveyor, Mechanical Drives

Finish

Untreated / Phosphate / Black Oxide (model dependent)

Key Features & Benefits

  • Customizable Bore: Machine the bore and keyway exactly as required.
  • Smooth Power Transfer: Precisely machined teeth ensure accurate chain engagement.
  • High-quality Steel made: Any types of metal work, 5” Heavy Duty.
  • Large Size Range: Will work small equipment all the way up to large industrial machinery.
  • Also compatible with BS standard: Suits all 1/2" pitch standard roller chains.
  • Bulk order discount: Great for OEMs, garages and maintenance facilities.

Why Choose Bolton Engineering Products Ltd?

As one of the UK’s trusted suppliers of pilot bore sprockets, BEP Ltd offers:

  • Large inventory of plain bore sprockets in multiple tooth counts
  • High-quality components sourced from reliable manufacturers
  • Competitive prices with trade & bulk discounts
  • Expert technical support for sizing and application queries
  • Fast UK dispatch with reliable shipping options

When you need precision, durability, and flexibility, BEP Ltd has the right pilot bore sprocket for your job.

FAQs

Q1: What is the difference between a pilot bore sprocket and a finished bore sprocket?

A pilot bore sprocket has an oversized bore that requires machining. A finished bore sprocket comes pre-machined to a specific shaft size.

Q2: Is a pilot bore the same as a plain bore?

Yes — plain bore sprockets and pilot bore sprockets describe the same unfinished, machinable bore design.

Q3: Can I machine the bore myself?

Yes. Many customers machine the bore, keyway, and grub-screw holes in-house. We can also advise on machining allowances.

Q4: Are these sprockets compatible with standard roller chains?

Absolutely. All our sprockets fit 1/2” pitch BS roller chains.

Roller Chain Pilot Bore Sprockets - 1/2"

Pilot Bore Sprockets – 1/2” Pitch Roller Chain Sprockets

At Bolton Engineering Products Ltd, we stock a full range of pilot bore sprockets designed for reliable, efficient power transmission in machinery, conveyors, automation systems, and chain-driven equipment.

These plain bore sprockets (Type A) have an unprepared bore and require a keyway and set screw for installation, allowing them to be fully customized to fit any shaft size and meet your specific needs.

BEP Ltd have you covered – whether it be a light-duty sprocket or an item designed for continuous use, all our parts are made from high-strength materials and custom machined to tight tolerances at very competitive prices.

What Is a Pilot Bore Sprocket?

A pilot bore sprocket is a chain sprocket supplied with a basic, oversized bore, allowing engineers or machinists to finish-machine it to the exact shaft diameter or keyway required.

These sprockets are popular in:

  • Manufacturing & processing equipment
  • Agricultural and industrial machinery
  • Conveyors and material handling systems
  • Motorcycles, bicycles & chain-driven vehicles
  • General engineering and fabrication workshops

Their flexibility makes them a go-to choice for custom drive systems and OEM applications.

Technical Specifications

Specification

Details

Product Type

Pilot Bore / Plain Bore Sprocket

Chain Pitch

1/2” Pitch (BS Standard Roller Chain)

Tooth Count Options

8T to 50T+

Material

C45 Steel / Hardened Steel

Bore Type

Pilot Bore (Machinable to Required Shaft Size)

Mounting Style

Direct Shaft, Hub, or Bushing Mount

Tooth Profile

British Standard (BS / ISO Chain)

Applications

Industrial, Agricultural, Conveyor, Mechanical Drives

Finish

Untreated / Phosphate / Black Oxide (model dependent)

Key Features & Benefits

  • Customizable Bore: Machine the bore and keyway exactly as required.
  • Smooth Power Transfer: Precisely machined teeth ensure accurate chain engagement.
  • High-quality Steel made: Any types of metal work, 5” Heavy Duty.
  • Large Size Range: Will work small equipment all the way up to large industrial machinery.
  • Also compatible with BS standard: Suits all 1/2" pitch standard roller chains.
  • Bulk order discount: Great for OEMs, garages and maintenance facilities.

Why Choose Bolton Engineering Products Ltd?

As one of the UK’s trusted suppliers of pilot bore sprockets, BEP Ltd offers:

  • Large inventory of plain bore sprockets in multiple tooth counts
  • High-quality components sourced from reliable manufacturers
  • Competitive prices with trade & bulk discounts
  • Expert technical support for sizing and application queries
  • Fast UK dispatch with reliable shipping options

When you need precision, durability, and flexibility, BEP Ltd has the right pilot bore sprocket for your job.

FAQs

Q1: What is the difference between a pilot bore sprocket and a finished bore sprocket?

A pilot bore sprocket has an oversized bore that requires machining. A finished bore sprocket comes pre-machined to a specific shaft size.

Q2: Is a pilot bore the same as a plain bore?

Yes — plain bore sprockets and pilot bore sprockets describe the same unfinished, machinable bore design.

Q3: Can I machine the bore myself?

Yes. Many customers machine the bore, keyway, and grub-screw holes in-house. We can also advise on machining allowances.

Q4: Are these sprockets compatible with standard roller chains?

Absolutely. All our sprockets fit 1/2” pitch BS roller chains.

4SR24 32mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 32mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):32mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 30mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 30mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):30mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 28mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 28mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):28mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 25mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 25mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):25mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 24mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 24mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):24mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 22mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 22mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):22mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR24 20mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

Roller Chain Sprocket 08B 4SR24 20mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):20mmMf...

View full details
£17.81 - £17.81
£17.81
£17.81 - £17.81
£17.81

4SR23 38mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 38mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):38mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 35mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 35mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):35mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 32mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 32mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):32mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 28mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 28mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):28mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 25mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 25mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):25mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 24mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 24mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):24mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 22mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 22mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):22mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR23 20mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 23 Tooth

£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

Roller Chain Sprocket 08B 4SR23 20mm Bore Key & 2 Set Screws 1/2" Pitch 23 ToothChain Pitch:08B-1Number of Teeth:23Bore & Keyway(mm):20mmMf...

View full details
£16.98 - £16.98
£16.98
£16.98 - £16.98
£16.98

4SR21 35mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 35mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):35mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 32mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 32mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):32mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 30mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 30mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):30mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 28mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 28mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):28mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 25mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 25mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):25mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 24mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 24mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):24mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 22mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 22mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):22mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 20mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 20mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):20mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

4SR21 19mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 21 Tooth

£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Roller Chain Sprocket 08B 4SR21 19mm Bore Key & 2 Set Screws 1/2" Pitch 21 ToothChain Pitch:08B-1Number of Teeth:21Bore & Keyway(mm):19mmMf...

View full details
£15.30 - £15.30
£15.30
£15.30 - £15.30
£15.30

Hi. Need any help?