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SAE J626-2015: End-Mounting Flanges for Diesel Fuel Injection Pumps
Standard Overview and Rationale
SAE J626-2015 specifies dimensional requirements for eight types of end-mounting flanges for fuel injection pumps in diesel engines. Although the standard was cancelled in November 2015 and superseded by ISO 7299-1, it remains a reference for legacy designs and offers insight into flange interface standardization.
⚠️ Important: SAE J626 was cancelled in 2015. Always refer to ISO 7299-1 for current designs unless working with existing systems.
Dimensional Specifications and Tolerance Guidance
The standard defines detailed dimensions for each of the eight flange types, with tolerances for critical features such as the pump spigot (A) and female register diameter. For example, the spigot tolerance is typically g8, while the female register is encouraged to be H8. These tolerances ensure proper fit and interchangeability between pumps and engines.
🛠️ Design Insight: Tolerances can be adjusted by mutual agreement—g8 can be replaced with f7, and H8 with H7, if functionally necessary. This flexibility allows engineers to optimize fit for specific applications.
Flange Type Dimensions
| Flange Type | A (mm) g8 | B (nominal) mm | C ±0.5 mm | D max mm | E min mm |
|---|---|---|---|---|---|
| Type 1 | 50 or 68 | 17 or 20 | 12.5 or 26 | 11 or 24.5 | 13–16 |
| Type 2 | 50 or 68 | 17 or 20 | 12.5, 17.4, or 26 | 11, 16, or 24.5 | 13–16 |
| Type 3 | 50 or 68 | 17 or 20 | 9.5, 12.5, 17.4, or 26 | 8.2, 11, 16, or 24.5 | 13–16 |
| Type 4 | 68 | 17 | 9.5 | 8 | 10–16 |
| Type 5 | 74 or 76 | 17 | 9.5 | 8 | 8–10 |
| Type 6 | 68, 97, or 112 | 20 or 22 | 4.5 (C ±1) | 7.5 | 17–18 or 24–26 |
| Type 7 | 68 or 85 | 17, 20, 22, or 25 | 4.5, 9.5, 12.5, or 17.4 | 8.2, 11, or 16 | 15–18 |
| Type 8 | 95 or 107 | 20, 25, 30, or 35 | 9.5, 13.5, or 18.5 | 8.2, 12, or 17 | 17–20 |
Note: For Type 6, tolerance for C is ±1 mm; for all others, ±0.5 mm. Dimensions B refer to shaft end tapers per SAE J1419.
Insight: When selecting a flange type, consider factors such as pump size, mounting pattern, and shaft end tapers, which are defined in SAE J1419. The specification of H8 for female register and g8 for spigot ensures proper fit, but mutual agreement can adjust these tolerances if needed.
Frequently Asked Questions
Why was SAE J626 cancelled?
The standard was cancelled to eliminate redundancy with ISO 7299-1, which fully covers the same content. This aligns with the trend toward international standardization in diesel fuel injection components.
How do I adjust tolerances for a better fit?
By mutual agreement, the spigot tolerance g8 can be replaced with f7, and the register tolerance H8 with H7, if functional requirements dictate. Always verify with the pump and engine manufacturers.
What is the role of SAE J1419?
SAE J1419 specifies tapers for shaft ends and hubs for fuel injection pumps, which are referenced in J626 for flange types. It is essential for ensuring proper shaft interface.
Can I still use SAE J626 for new designs?
While it is cancelled, J626 may be referenced for legacy systems. However, new designs should follow ISO 7299-1 to ensure compliance with current standards.
