Bell Approved Processes for Precision Finishing and Testing
Magnetic Inspection Laboratory, Inc. (MIL) is a trusted processor for Bell, delivering specialized finishing and testing for defense and industrial components. As an approved provider, MIL meets Bell’s rigorous standards through processes like anodizing, black oxide, cadmium plating, chem film, chemical milling, electropolishing, non-destructive testing (NDT), and welding, backed by Nadcap and AS9100 certifications. With 82 years of expertise, we ensure precision and compliance across multiple industries. Search the table below by process or specification to verify our capabilities.
| PROCESS CODE | SPECIFICATION | DESCRIPTION |
REMARKS |
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| ANODIZING | PA | BPS 4001 / MIL-A-8625 TY I, TY IB | CHROMIC ACID |
✔ |
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| PD1 | BPS 4387 / MIL-A-8625 TY III | HARD ANODIZING |
✔ |
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| PD2 | BPS 4387 | HARD ANODIZING (PTFE, TFE COATING) |
✔ |
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| PD3 | BPS 4387 / MIL-A-8625 TY III | HARD ANODIZING (PTFE, TFE SEALED) |
✔ |
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| PM | BPS 4555* / MIL-A-8625 TY IIB | SULFURIC ACID * See note |
✔ |
* SEE NOTE 1 BELOW, APPLIES TO BPS 4555 ONLY | |
| BLACK OXIDE | PF | BPS 4084 | BLACK OXIDE |
✔ |
|
| CAD PLATING | PB | BPS4006 / AMS-QQ-P-416 TY I,II, III | CADMIUM PLATE |
✔ |
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| CHEM FILM | QB1 | BPS 4182 / MIL-DTL-5541 TY I | CL 1A |
✔ |
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| QB2 | BPS 4182 / MIL-DTL-5541 TY I | CL 3 |
✔ |
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| CHEM MILL | QE2 | BPS 4389 / MIL-C-81769 / AMS-C-81769 | LOW ALLOY STEEL |
✔ |
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| QE3 | BPS 4389 / MIL-C-81769 / AMS-C-81769 | STAINLESS & HIGH ALLOY |
✔ |
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| QE5 | BPS 4389 / MIL-C-81769 / AMS-C-81769 | TITANIUM |
✔ |
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| QE6 | BPS 4389 / MIL-C-81769 / AMS-C-81769 | FORGINGS |
✔ |
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| EPOLISH | BPS 4501 |
✔ |
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| ETCH | QE7 | BPS 4389 | PRE PENETRANT ETCH AL. CASTING |
✔ |
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| CLEANING | PS | BPS 4138 | CHEMICAL |
✔ |
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| SN4 | BPS 4462 | CLEAN & DESCALE.OF TI MAT’L |
✔ |
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| DFL | QI | BPS 4310 / MIL-L-23398 / MIL-PRF-46010 |
✔ |
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| PASS | QJ1 | BPS 4007 / AMS 2700 ALL TY 1-4 | PROCEDURE I |
✔ |
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| QJ2 | BPS 4007 / AMS 2700 ALL TY 1-4 | PROCEDURE II |
✔ |
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| PHOSPHATE | QC | BPS 4384 | STEEL |
✔ |
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| MIL-P-16232 / MIL-DTL-16232 | Type M only |
✔ |
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| NDE | IA | BPS 4075 / ASTM E 1444 | MAG PARTICLE |
✔ |
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| IB3 | BPS 4089 / ASTM E 1417 | FPI (WATER WASHABLE) CSTGS; INCLUDES IB1. |
✔ |
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| IB4 | BPS 4089 | FPI (POST-EMULSIFIED) CSTGS/FORG.; INCLUDES IB2. |
✔ |
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| IF1 | BPS 4309 / ASTM E 1742 | RADIOGRAPHIC |
✔ |
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| IF2 | BPS 4309 / ASTM E 1742 | RADIOGRAPHIC |
✔ |
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| WELDING | NJ1 | BPS 4470 | WELDING(IN PROCESS CASTINGS) AL 356/A356/357 ALLOYS |
✔ |
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| for BPS 4555 but lists BPS 4001 chromic acid anodize as an alternate, MIL can process the part per BPS 4001 and BPS 4001 only. | |||||
| THE PROCESSES COVERED BY THE FOLLOWING LISTED SPECIFICATIONS REQUIRE BELL APPROVAL : | |||||
| 4001 | 4357 Sect IV | 4458 | 4531 | 4595 | |
| 4003 | 4359 | 4460 | 4541 | 4596 | |
| 4006 | 4364 | 4462 | 4542 | 4597 | |
| 4007 | 4366 | 4463 | 4543 | 4599 | |
| 4012 | 4383 | 4465 | 4544 | 4600 | |
| 4017 | 4384 | 4467 | 4546 | 4601 | |
| 4022 | 4387 | 4469 | 4548 | ||
| 4075 | 4389 | 4470 | 4549 | ||
| 4083 | 4400 | 4478 | 4551 | ||
| 4084 | 4401 | 4487 | 4552 | ||
| 4089 | 4402 | 4488 | 4553 | ||
| 4092 | 4403 | 4490 | 4554 | ||
| 4098 | 4404 | 4491 | 4555 | ||
| 4110 | 4408 | 4492 | 4556 | ||
| 4113 | 4409 | 4495 | 4558 | ||
| 4138 | 4419 | 4496 | 4563 | ||
| 4139 | 4420 | 4501 | 4570 | ||
| 4140 | 4424 | 4503 | 4574 | ||
| 4162 | 4425 | 4508 | 4578 | ||
| 4163 | 4431 | 4509 | 4579 | ||
| 4182 | 4432 | 4510 | 4580 | ||
| 4207 | 4436 | 4511 | 4581 | ||
| 4212 | 4437 | 4512 | 4582 | ||
| 4302 | 4439 | 4513 | 4583 | ||
| 4304 | 4440 | 4514 | 4584 | ||
| 4305 | 4445 | 4517 | 4586 | ||
| 4309 | 4446 | 4518 | 4587 | ||
| 4310 | 4448 | 4520 | 4588 | ||
| 4312 | 4449 | 4522 | 4589 | ||
| 4328 | 4453 | 4523 | 4590 | ||
| 4339 | 4454 | 4525 | 4591 | ||
| 4351 | 4455 | 4528 | 4592 | ||
| 4352 | 4456 | 4529 | 4594 | ||
MIL’s Bell approvals reflect our long-standing commitment to precision and reliability for primes and machine shops. Our one-stop-shop capabilities and rigorous contract reviews ensure consistent quality and on-time delivery (93%+ OTD).
Request a fast quote (48–72 hours) or explore our full list of 2,500+ prime approvals.