Baldwin BT525 vs FRAM HPH3506: Oil Filter Compatibility
Compare Baldwin BT525 and FRAM HPH3506 oil filters by compatibility, dimensions, thread size, gasket fit, bypass valve, anti-drainback valve status, and match confidence. Use this comparison as a fitment review, not as an automatic substitution guarantee. Both use a 13/16-16 thread.
Quick verdict
Both use a 13/16-16 thread.
- Thread size is the first hard-fit check for any comparison of spin-on filters.
- Gasket OD and gasket ID are the most important seal-related dimensions.
- Height differences can matter for clearance even when thread and gasket fit appear close.
- Bypass and anti-drainback differences may be important, depending on the application.
Baldwin BT525 and FRAM HPH3506 specifications
How matching is scored| Specification | Baldwin BT525 | FRAM HPH3506 |
|---|---|---|
| Thread size | 13/16-16 | 13/16-16 |
| Gasket OD | 71.4 mm | 71.1 mm |
| Gasket ID | 62.7 mm | 62.5 mm |
| Can OD | 93.7 mm | 74.7 mm |
| Height | 221.5 mm | 87.1 mm |
| Internal bypass valve | No | No |
| Bypass PSID | Not applicable | Not applicable |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are 13/16-16.
Gasket OD differs by 0.3 mm (Baldwin BT525: 71.4 mm, FRAM HPH3506: 71.1 mm).
Gasket ID differs by 0.2 mm (Baldwin BT525: 62.7 mm, FRAM HPH3506: 62.5 mm).
Baldwin BT525 is 134.4 mm taller (Baldwin BT525: 221.5 mm, FRAM HPH3506: 87.1 mm) -- check clearance before substituting.
Can OD differs by 19 mm (Baldwin BT525: 93.7 mm, FRAM HPH3506: 74.7 mm).
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.