Description
21-5P25-6FS3 Powerhouse® Timing Pulley, 21 Teeth, 5P Pitch
The 21-5P25-6FS3 is a 21-tooth 5 mm Powerhouse® curvilinear timing pulley with a 1/4 in minimum plain bore, machined from steel with a black oxide finish, built for 25mm wide belts. Machined from solid stock, never sintered or powdered metal. The Powerhouse® modified curvilinear profile carries roughly twice the load of a standard curvilinear pulley of the same size.
Specifications

Dimension key for this construction type. Values for this part number are in the table below.
| Specification | Value |
|---|---|
| Part Number | 21-5P25-6FS3 |
| Teeth | 21 |
| Pitch | 5 mm Powerhouse® curvilinear |
| For Belt Width | 25mm |
| Pitch Diameter | 1.3158 in |
| Outside Diameter | 1.2708 in |
| Flange Diameter | 1.531 in |
| Bore | 1/4 in minimum plain bore |
| Face Width | 1.28 in |
| Overall Length | 1.65 in |
| Hub Diameter | 0.9 in |
| Construction | Standard Hub |
| Flange Material | Steel |
| Material | Steel (no sintered or powdered metal) |
| Finish | Black Oxide |
| Weight | 0.496 lb |
| Country of Origin | United States. ISO 9001:2015 certified manufacturing. |
Applications
- Higher load synchronous drives in compact spaces
- Industrial automation and conveyor drives
- Packaging and material handling equipment
Belt Compatibility
The 21-5P25-6FS3 runs 5 mm Powerhouse® curvilinear belts in 25mm width. The pitch is standardized, so belt and pulley brands can be mixed.
Cross Reference
The 21-5P25-6FS3 interchanges with these equivalent part numbers, per published manufacturer interchange data:
| Manufacturer | Equivalent Part Number |
|---|---|
| Gates® | P21-5MGT-25-MPB |
| Neuman | 5MR-21S-25 |
| Grainger | 809TC4 |
| Powerdrive | 21-5P25-6FS3 |
| Continental (ContiTech) | P21-5M-25-MPB QTE |
Always verify dimensions and bore size before substituting part numbers across manufacturers.
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Multi-unit and OEM quantities qualify for volume discounts. Call or email for a quantity quote.
Frequently Asked Questions
What belts fit the 21-5P25-6FS3 pulley?
5 mm Powerhouse® curvilinear timing belts in 25mm width from any manufacturer. The pitch is standardized, so belt and pulley brands can be mixed.
Does the 21-5P25-6FS3 replace the Gates P21-5MGT-25-MPB?
Yes. Published interchange data crosses the 21-5P25-6FS3 directly to the Gates P21-5MGT-25-MPB, as well as Neuman 5MR-21S-25, Grainger 809TC4, Powerdrive 21-5P25-6FS3. Verify dimensions and bore before ordering.
Does the 21-5P25-6FS3 ship from Houston?
Yes. Stock items ship same day from our Houston, Texas warehouse. Call (888) 203-2358 to confirm availability.
Need a quote on 21-5P25-6FS3?
Houston warehouse, same-day shipping on stock items.
Call (888) 203-2358Powerhouse® is a registered trademark of its owner. HTD® is a registered trademark of Gates Corporation. All third-party part numbers and trademarks referenced are the property of their respective owners. References are for compatibility identification only and do not imply affiliation or endorsement.
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