Baldwin Filters · Form 561 Interchange · inline line
BT8421-MPG filter element: specifications & equivalents
The BT8421-MPG is a Baldwin Filters inline-line hydraulic filter element. Verify against the current manufacturer data sheet before ordering.
Line type inline
Partially verified. Fit and grade trace to an official interchange document;
dimensional values are compiled from 0 aftermarket listing(s)
and must be confirmed against the manufacturer housing drawing. Confidence score 0.80.
Form 561 is a cross-reference only — Baldwin prints no dimensions, micron rating, collapse pressure or seal data for this part number here. Verify every specification against the current Baldwin data sheet before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | inline line |
| Integral bypass valve | none (housing/valve-dependent) |
| Manufacturer part no. | BT8421-MPG |
| Source catalog | Baldwin Filters: Baldwin Filters Form 561 |
| Last verified | 2026-09-30 |
Sources: Baldwin Filters — Baldwin Filters Form 561 — accessed 2026-09-30.
Baldwin Filters® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized Baldwin Filters distributor.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
|
↔ AR750H0403 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists AR750H0403 (FAIREY-ARLON) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ B7160175 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists B7160175 (MOOG) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ DV0211B1V03 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists DV0211B1V03 (VICKERS) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ HF6703 | Fleetguard | partial | Baldwin's Form 561 Number-Finder cross-reference lists HF6703 (FLEETGUARD) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ HF6704 | Fleetguard | partial | Fleetguard's online catalog lists BT8421MPG as an interchange for HF6704. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ HF6775 | Fleetguard | partial | Baldwin's Form 561 Number-Finder cross-reference lists HF6775 (FLEETGUARD) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ NFC1058 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists NFC1058 (FAIREY-ARLON) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RMFE16003BN2 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists RMFE16003BN2 (HYCON) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ SF-6703-MG | STAUFF | partial | STAUFF Filter Interchange lists BT 8421-MPG (BALDWIN) as replaced by SF-6703-MG. Envelope dimensions are published; media grade and performance data are not — confirm before substituting in cleanliness-critical circuits. |
|
↔ UA722661 page in verification queue | Aftermarket | partial | Baldwin's Form 561 Number-Finder cross-reference lists UA722661 (MOOG) as replaced by Baldwin BT8421-MPG. Form/fit listing without published performance data — verify micron grade, collapse rating and seal configuration before substituting. |
Interchange levels: full catalog-confirmed drop-in · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the BT8421-MPG model number is decoded
- BT8421-MPGBaldwin filter part number per the Form 561 Number-Finder cross-reference.
Typical equipment & applications
- Hydraulic / transmission filtration — listed in the Baldwin Form 561 Number-Finder cross-reference.
Selection pitfalls — read before you substitute
- “10 µm nominal” and “12 µm at β1000” can describe the very same media — one is reported at β≥200, the other at β≥1000 per ISO 16889. Compare ratings at the same Beta test point, not just the printed micron number.
- Nitrile (NBR) seals are standard for mineral hydraulic oil but fail early in some phosphate-ester fluids and at sustained high temperature; verify seal compound against the fluid data sheet (fluorocarbon/Viton executions may be required).
- End-cap geometry and the number/position of O-rings block interchange even when OD and length match — visually compare end caps before fitting, especially with aftermarket cartridges.
Frequently asked questions
What replaces the BT8421-MPG filter element?
10 partial match(es) requiring parameter review
How do I read the BT8421-MPG part number?
See the designation decoder above: each segment of BT8421MPG encodes size, line type, filtration grade and media/collapse execution.
Is a same-envelope aftermarket element always a drop-in replacement?
No. Matching OD and length only proves the cartridge fits the bowl. End-cap style, seal compound, micron/Beta rating, collapse pressure and bypass configuration must also match; the table above tags every equivalent as full, partial or verify for exactly this reason.
How often should a hydraulic return-line element be replaced?
Replace at the housing manufacturer’s recommended differential-pressure setting (commonly signalled by a clogging indicator), or on a time-based service interval when no indicator is fitted — never wait for bypass to open continuously, because unfiltered oil then reaches the valves.
Other models in the Form 561 Interchange series
All 1208 →Reviewed & verified by the ElementRef engineering desk against Baldwin Filters on 2026-09-30. Read our editorial & correction policy.