Blind-Hole Sensor Housing
Blind-Hole Sensor Housing
304 stainless steel pressure/temperature sensor shell — one draw plus ironing.
| Material | 304 stainless steel |
|---|---|
| Draw depth | 62 mm |
| Wall thickness | 0.8 → 0.62 mm (ironed) |
| Tolerance | ±0.05 mm |
| Press | 200 T |
| Forming route | Single draw + ironing |
| Measured LDR | 1.85–2.05 |
The challenge
The part is a blind-hole shell: the bottom must seal with no leak path for a pressure sensor, the wall must stay uniform so the body can be welded or crimped to a fitting, and the outside diameter cannot drift or the seal geometry fails. A drawn wall that varies by a few hundredths is enough to make the weld fixture reject the part.
The blind bottom is formed as one piece with the wall, so there is no welded seam to leak — but that also means the bottom radius has to be set in the same stroke as the wall, which is why the die radius and punch profile are tuned to this 304 coil rather than a generic set.
Downstream, the housing is welded or crimped to a fitting and the open end often carries a connector, so the outside diameter and the wall at the joint have to be exact. The draw and iron is set so the seal geometry lands where the mating part expects it.
How AUNOV draws it
The 200 T press gives enough capacity to draw the 62 mm depth in a single stroke while controlling the bottom radius, and the ironing pass that follows sets the wall without touching the sealed bottom.
- Blank sized from the measured 304 limiting draw ratio (1.85–2.05) rather than a generic cup formula
- Single draw on a 200 T press, with die radius set for the 62 mm depth
- Ironing pass to bring the wall from 0.8 mm to 0.62 mm and set the wall tolerance
- CMM first-article check on diameter, depth and wall uniformity before release
Process control and inspection
A CMM first-article checks diameter, depth and wall uniformity, then we sample those same points through the lot, because a welded or crimped fitting depends on the wall landing in the same place every time.
The sealed blind bottom is verified by a pressure test on the first article, since the whole point is that there is no weld seam to leak; we confirm the bottom radius holds before release.
What this means for your part
If your sensor housing is a blind-drawn stainless steel shell in this size class, the 304 route above is already proven in production. Tell us the seal or weld interface and we size the wall and bottom radius to suit it.
For production we run a CMM first-article on diameter, depth and wall uniformity, then sample those same points through the lot so a welded or crimped fitting keeps seating the same way every time.
- Tell us the seal or weld interface; the wall and bottom radius are sized to it.
- Keep the outside diameter as a controlled feature, because the seal geometry fails if it drifts.
- If a connector passes through the open end, give its position so we hold the wall there.
Frequently asked questions
Can a blind-hole sensor housing be deep drawn without a welded bottom?
Direct answer: Yes. The blind bottom is formed in the same draw as the wall, so there is no weld seam to leak. AUNOV draws the shell in one hit and then irons the wall to the required tolerance, which keeps the bottom and wall as one continuous piece.
What wall tolerance can a drawn sensor housing hold?
Direct answer: AUNOV holds ±0.05 mm on the drawn diameter and wall, and ±0.02 mm after ironing. The ironing pass is what sets the tighter wall, rather than relying on the draw alone.
Why draw a sensor housing on a 200 T press?
Direct answer: The 200 T press gives the capacity to form the 62 mm blind depth and the bottom radius in a single stroke while keeping the wall controlled. AUNOV then irons the wall to 0.62 mm, so the sealed bottom and the uniform wall are set in two controlled steps rather than one uncertain one.
Have a similar part?
Send the drawing and material — AUNOV returns a DFM review and a quote within 24 hours.
Request a quoteSources Behind These Examples
Each example is built on measured material data and the process taxonomy set out by these standards. We keep the lot data behind each part on file for first-article review.
- ASTM E646 — Standard Test Method for Tensile Strain-Hardening Exponents (n) of Metallic Sheet Materials. The n-value sets how much a wall can thin before necking.
- DIN 8584 — Manufacturing processes, forming: classification of deep drawing operations and their subgroups.
- ISO 20482 — Metallic materials: Erichsen cupping test, a formability measure complementary to LDR.
- Wikipedia: Anisotropy — explains the r-value and why earing directions form.
- Wikipedia: Work hardening — why redraws and intermediate annealing matter.