Fleetguard · HF Hydraulic · return line
HF6521 filter element: specifications & equivalents
The HF6521 is a Fleetguard return-line hydraulic filter element, sized 93.47 × 205.49 mm OD × length. Verify against the current manufacturer data sheet before ordering.
Envelope OD × L 93.47 × 205.49 mm
Line type return
Catalog verified. Parameters extracted from the manufacturer’s electronic
catalog / official interchange document and checked 2026-09-28. Confidence score 0.90.
Specifications and cross-references are taken from the Fleetguard online catalog API. Where both TWA and Beta ratings are published the conventions differ — verify cleanliness targets, collapse rating and seal configuration against the current Fleetguard data sheet before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | return line |
| Outside diameter OD | 93.47 mm |
| Length | 205.49 mm |
| End caps | spin-on baseplate with attached gasket |
| Flow direction | outside-in |
| Integral bypass valve | none (housing/valve-dependent) |
| Manufacturer part no. | HF6521 |
| Source catalog | Cummins Filtration / Fleetguard: Fleetguard online product catalog (fleetguard.com) |
| Last verified | 2026-09-28 |
Sources: Cummins Filtration / Fleetguard — Fleetguard online product catalog (fleetguard.com) — accessed 2026-09-28.
Fleetguard® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized Fleetguard distributor.
Dimensions & series range
| Outside diameter | 93.47 mm (3.680 in) |
| Overall length | 205.49 mm (8.090 in) |
All 93×205 mm interchange elements →
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
|
↔ 12428093 page in verification queue | UFI | partial | Fleetguard's online catalog lists 12428093 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 20202 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 20202 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 30895 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 30895 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 410 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 410 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 5381318 page in verification queue | UFI | partial | Fleetguard's online catalog lists 5381318 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 5839HF6521 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 5839HF6521 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 59026500 page in verification queue | UFI | partial | Fleetguard's online catalog lists 59026500 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 61000322 page in verification queue | UFI | partial | Fleetguard's online catalog lists 61000322 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 7008825030 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 70088 25030 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 70095 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 70095 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 70147 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 70147 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 7SL6020P25 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 7SL6020P25 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ 85MA010P page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists 85MA010P as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ AE10L page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists AE10L as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ BT8903 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists BT8903 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ CA152AFD1 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists CA152AFD1 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ CSG070P10 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists CSG070P10 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ CSG70P10A page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists CSG70P10A as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ DMS07BN page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists DMS07BN as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ E0121B2P10 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists E0121B2P10 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ F4E040DCB page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists F4E040DCB as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ FPE4010N page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists FPE4010N as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HC51 page in verification queue | Pall | partial | Fleetguard's online catalog lists HC51 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HF0652100 page in verification queue | Fleetguard | partial | Fleetguard's online catalog lists HF0652100 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ HF0652100JX page in verification queue | Fleetguard | partial | Fleetguard's online catalog lists HF0652100JX as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ MFE801252 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists MFE801252 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ P550256 page in verification queue | Donaldson | partial | Fleetguard's online catalog lists P550256 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ P565060 | Donaldson | partial | Fleetguard's online catalog lists P565060 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ PSL963 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists PSL963 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ RSE4025N page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists RSE4025N as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ SF-6521 | STAUFF | partial | Fleetguard's online catalog lists SF6521 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ SH56571 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists SH56571 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ ST6521 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists ST6521 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
|
↔ TRA5715132 page in verification queue | Aftermarket | partial | Fleetguard's online catalog lists TRA5715132 as an interchange for HF6521. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ WD962 | MANN-FILTER | partial | MANN-FILTER's online catalog lists HF6521 (FLEETGUARD/CUMMINS FILTRATION) as a comparison number for WD962. Envelope cross-reference; 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 HF6521 model number is decoded
- HF6521Fleetguard HF-series hydraulic spin-on filter part number.
- 205.49 mmOverall height.
- 93.47 mmLargest outside diameter.
Typical equipment & applications
- Construction, agricultural and industrial hydraulic circuits
- Mobile-equipment hydraulic return and pressure lines
Selection pitfalls — read before you substitute
- A return-line element is not a pressure-line element: return cartridges (BN4HC low-collapse) tolerate roughly 20 bar differential, while BH4HC pressure executions are rated to 210 bar. Installing a low-collapse element in a pressure housing can rupture the media on cold-start spikes.
- This element has no integral bypass — opening pressure is set by the housing’s reusable bypass valve. Confirm the valve setting (commonly 3.4 bar) is present before fitting.
- “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 are the dimensions of the HF6521 filter element?
The published envelope is 93.47 mm OD × 205.49 mm length (3.680 × 8.090 in). Confirm against the housing drawing before ordering.
What replaces the HF6521 filter element?
35 partial match(es) requiring parameter review
How do I read the HF6521 part number?
See the designation decoder above: each segment of HF6521 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.
Same-envelope elements from other brands
View full interchange →These 8 catalog element(s) share the 93×205 mm envelope. Envelope match alone does not guarantee interchangeability — compare micron/Beta, seals and collapse rating.
Other models in the HF Hydraulic series
All 2621 →Reviewed & verified by the ElementRef engineering desk against Cummins Filtration / Fleetguard on 2026-09-28. Read our editorial & correction policy.