FRAM PH4703 vs Baldwin B173-S: Oil Filter Compatibility
Compare FRAM PH4703 and Baldwin B173-S 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 M20x1.5 thread.
Quick verdict
Both use a M20x1.5 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.
FRAM PH4703 and Baldwin B173-S specifications
How matching is scored| Specification | FRAM PH4703 | Baldwin B173-S |
|---|---|---|
| Thread size | M20X1,5 | M20x1.5 |
| Gasket OD | 71.1 mm | 71.4 mm |
| Gasket ID | 62.5 mm | 62.7 mm |
| Can OD | 86 mm | 93.7 mm |
| Height | 89 mm | 82.6 mm |
| Internal bypass valve | Yes | Yes |
| Bypass PSID | 12 | 20 |
| Anti-drainback valve | Yes | Yes |
What matters in this specific comparison
Thread size matches: both are M20x1.5.
Gasket OD differs by 0.3 mm (FRAM PH4703: 71.1 mm, Baldwin B173-S: 71.4 mm).
Gasket ID differs by 0.2 mm (FRAM PH4703: 62.5 mm, Baldwin B173-S: 62.7 mm).
FRAM PH4703 is 6.4 mm taller (FRAM PH4703: 89 mm, Baldwin B173-S: 82.6 mm) -- check clearance before substituting.
Can OD differs by 7.7 mm (FRAM PH4703: 86 mm, Baldwin B173-S: 93.7 mm).
Both open their bypass valve in a comparable range: FRAM PH4703 at 12-12 psi, Baldwin B173-S at 20-20 psi -- these ranges do not overlap.
Open related filters
Before substituting, verify thread fit, gasket sealing dimensions, height clearance, bypass behavior, and anti-drainback requirements for your specific application.