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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.

4DR38C (08B-2-38) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 38 Tooth

Original price £39.06 - Original price £39.06
Original price
£39.06
£39.06 - £39.06
Current price £39.06

4DR38C (08B-2-38) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 38 Tooth

Original price £39.06 - Original price £39.06
Original price
£39.06
£39.06 - £39.06
Current price £39.06

4DR45C (08B-2-45) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 45 Tooth

Original price £41.72 - Original price £41.72
Original price
£41.72
£41.72 - £41.72
Current price £41.72

4DR45C (08B-2-45) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 45 Tooth

Original price £41.72 - Original price £41.72
Original price
£41.72
£41.72 - £41.72
Current price £41.72

4DR57C (08B-2-57) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 57 Tooth

Original price £43.33 - Original price £43.33
Original price
£43.33
£43.33 - £43.33
Current price £43.33

4DR57C (08B-2-57) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 57 Tooth

Original price £43.33 - Original price £43.33
Original price
£43.33
£43.33 - £43.33
Current price £43.33

4DR76C (08B-2-76) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 76 Tooth

Original price £75.76 - Original price £75.76
Original price
£75.76
£75.76 - £75.76
Current price £75.76

4DR76C (08B-2-76) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 76 Tooth

Original price £75.76 - Original price £75.76
Original price
£75.76
£75.76 - £75.76
Current price £75.76

4DR95C (08B-2-95) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 95 Tooth

Original price £97.75 - Original price £97.75
Original price
£97.75
£97.75 - £97.75
Current price £97.75

4DR95C (08B-2-95) - BS Duplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 95 Tooth

Original price £97.75 - Original price £97.75
Original price
£97.75
£97.75 - £97.75
Current price £97.75

4TR38C (08B-3-38) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 38 Tooth

Original price £51.86 - Original price £51.86
Original price
£51.86
£51.86 - £51.86
Current price £51.86

4TR38C (08B-3-38) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 38 Tooth

Original price £51.86 - Original price £51.86
Original price
£51.86
£51.86 - £51.86
Current price £51.86

4TR45C (08B-3-45) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 45 Tooth

Original price £53.83 - Original price £53.83
Original price
£53.83
£53.83 - £53.83
Current price £53.83

4TR45C (08B-3-45) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 45 Tooth

Original price £53.83 - Original price £53.83
Original price
£53.83
£53.83 - £53.83
Current price £53.83

4TR57C (08B-3-57) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 57 Tooth

Original price £81.43 - Original price £81.43
Original price
£81.43
£81.43 - £81.43
Current price £81.43

4TR57C (08B-3-57) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 57 Tooth

Original price £81.43 - Original price £81.43
Original price
£81.43
£81.43 - £81.43
Current price £81.43

4TR76C (08B-3-76) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 76 Tooth

Original price £122.67 - Original price £122.67
Original price
£122.67
£122.67 - £122.67
Current price £122.67

4TR76C (08B-3-76) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 76 Tooth

Original price £122.67 - Original price £122.67
Original price
£122.67
£122.67 - £122.67
Current price £122.67

4TR95C (08B-3-95) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 95 Tooth

Original price £168.03 - Original price £168.03
Original price
£168.03
£168.03 - £168.03
Current price £168.03

4TR95C (08B-3-95) - BS Triplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 95 Tooth

Original price £168.03 - Original price £168.03
Original price
£168.03
£168.03 - £168.03
Current price £168.03

4SR30 38mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 30 Tooth

Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

Roller Chain Sprocket 08B 4SR30 38mm Bore Key & 2 Set Screws 1/2" Pitch 30 ToothChain Pitch:08B-1Number of Teeth:30Bore & Keyway(mm):38mmMf...

View full details
Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

4SR30 32mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 30 Tooth

Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

Roller Chain Sprocket 08B 4SR30 32mm Bore Key & 2 Set Screws 1/2" Pitch 30 ToothChain Pitch:08B-1Number of Teeth:30Bore & Keyway(mm):32mmMf...

View full details
Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

4SR30 30mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 30 Tooth

Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

Roller Chain Sprocket 08B 4SR30 30mm Bore Key & 2 Set Screws 1/2" Pitch 30 ToothChain Pitch:08B-1Number of Teeth:30Bore & Keyway(mm):30mmMf...

View full details
Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

4SR30 28mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 30 Tooth

Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

Roller Chain Sprocket 08B 4SR30 28mm Bore Key & 2 Set Screws 1/2" Pitch 30 ToothChain Pitch:08B-1Number of Teeth:30Bore & Keyway(mm):28mmMf...

View full details
Original price £22.91 - Original price £22.91
Original price
£22.91
£22.91 - £22.91
Current price £22.91

4SR25 38mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 38mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):38mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 35mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 35mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):35mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 30mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 30mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):30mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 28mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 28mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):28mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 24mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 24mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):24mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 22mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 22mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):22mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR25 20mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 25 Tooth

Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

Roller Chain Sprocket 08B 4SR25 20mm Bore Key & 2 Set Screws 1/2" Pitch 25 ToothChain Pitch:08B-1Number of Teeth:25Bore & Keyway(mm):20mmMf...

View full details
Original price £17.67 - Original price £17.67
Original price
£17.67
£17.67 - £17.67
Current price £17.67

4SR24 38mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

Roller Chain Sprocket 08B 4SR24 38mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):38mmMf...

View full details
Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

4SR24 35mm Bore, Keyway & Grub Screws Roller Chain Sprocket 1/2" Pitch 24 Tooth

Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

Roller Chain Sprocket 08B 4SR24 35mm Bore Key & 2 Set Screws 1/2" Pitch 24 ToothChain Pitch:08B-1Number of Teeth:24Bore & Keyway(mm):35mmMf...

View full details
Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

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

Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

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
Original price £16.61 - Original price £16.61
Original price
£16.61
£16.61 - £16.61
Current price £16.61

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