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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.

4SR39 (08B-1-39) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 39 Tooth

Original price £11.31 - Original price £11.31
Original price
£11.31
£11.31 - £11.31
Current price £11.31

4SR39 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR39 Pitch 1/2 Teeth 39 Outside Dia (mm) 162.7 ...

View full details
Original price £11.31 - Original price £11.31
Original price
£11.31
£11.31 - £11.31
Current price £11.31

4SR37 (08B-1-37) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 37 Tooth

Original price £10.80 - Original price £10.80
Original price
£10.80
£10.80 - £10.80
Current price £10.80

4SR37 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR37 Pitch 1/2 Teeth 37 Outside Dia (mm) 154.6 ...

View full details
Original price £10.80 - Original price £10.80
Original price
£10.80
£10.80 - £10.80
Current price £10.80

4SR35 (08B-1-35) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 35 Tooth

Original price £9.77 - Original price £9.77
Original price
£9.77
£9.77 - £9.77
Current price £9.77

4SR35 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR35 Pitch 1/2 Teeth 35 Outside Dia (mm) 14.7 ...

View full details
Original price £9.77 - Original price £9.77
Original price
£9.77
£9.77 - £9.77
Current price £9.77

4SR34 (08B-1-34) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 34 Tooth

Original price £9.55 - Original price £9.55
Original price
£9.55
£9.55 - £9.55
Current price £9.55

4SR34 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR34 Pitch 1/2 Teeth 34 Outside Dia (mm) 142.6 ...

View full details
Original price £9.55 - Original price £9.55
Original price
£9.55
£9.55 - £9.55
Current price £9.55

4SR33 (08B-1-33) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 33 Tooth

Original price £9.24 - Original price £9.24
Original price
£9.24
£9.24 - £9.24
Current price £9.24

4SR33 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR33 Pitch 1/2 Teeth 33 Outside Dia (mm) 138.4 ...

View full details
Original price £9.24 - Original price £9.24
Original price
£9.24
£9.24 - £9.24
Current price £9.24

4SR32 (08B-1-32) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 32 Tooth

Original price £9.07 - Original price £9.07
Original price
£9.07
£9.07 - £9.07
Current price £9.07

4SR32 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR32 Pitch 1/2 Teeth 32 Outside Dia (mm) 134.3 ...

View full details
Original price £9.07 - Original price £9.07
Original price
£9.07
£9.07 - £9.07
Current price £9.07

4SR29 (08B-1-29) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 29 Tooth

Original price £7.29 - Original price £7.29
Original price
£7.29
£7.29 - £7.29
Current price £7.29

4SR29 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR29 Pitch 1/2 Teeth 29 Outside Dia (mm) 122 ...

View full details
Original price £7.29 - Original price £7.29
Original price
£7.29
£7.29 - £7.29
Current price £7.29

4SR28 (08B-1-28) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 28 Tooth

Original price £5.91 - Original price £5.91
Original price
£5.91
£5.91 - £5.91
Current price £5.91

4SR28 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR28 Pitch 1/2 Teeth 28 Outside Dia (mm) 118 ...

View full details
Original price £5.91 - Original price £5.91
Original price
£5.91
£5.91 - £5.91
Current price £5.91

4SR27 (08B-1-27) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 27 Tooth

Original price £5.71 - Original price £5.71
Original price
£5.71
£5.71 - £5.71
Current price £5.71

4SR27 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR27 Pitch 1/2 Teeth 27 Outside Dia (mm) 114 ...

View full details
Original price £5.71 - Original price £5.71
Original price
£5.71
£5.71 - £5.71
Current price £5.71

4SR26 (08B-1-26) - BS Simplex Roller Chain Sprocket Pilot Bore 08B 1/2" - 26 Tooth

Original price £5.54 - Original price £5.54
Original price
£5.54
£5.54 - £5.54
Current price £5.54

4SR26 Pilot Bore 08B 1/2" Pitch Sprocket For use with 08B-1 Simplex Chain Part Number 4SR26 Pitch 1/2 Teeth 26 Outside Dia (mm) 110 ...

View full details
Original price £5.54 - Original price £5.54
Original price
£5.54
£5.54 - £5.54
Current price £5.54

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