Dowel Pins for Plastic Mold
h7 tolerance tapped straight dowel pins in 52100 bearing steel (SUJ2) for precise injection mold plate alignment. The tapped end allows easy removal with a puller bolt — no damage to the mold plate during maintenance.
Dowel Pins
52100 Bearing Steel Tapped Dowel Pins — h7
Undersized h7 tolerance tapped straight dowel pins. 52100 bearing steel for precise jig and mold alignment.
H7 Undersized Tapped Dowel Pins
H7 undersized tapped dowel pins for plastic mold alignment. Accurate positioning with easy assembly.
Tapped vs Plain Dowel Pins — Which to Specify
| Dimension | Tapped Dowel Pins | Plain Dowel Pins |
|---|---|---|
| Removal Method | Puller bolt threaded into tapped end | Driven out from opposite side with punch |
| Plate Damage Risk | None — controlled extraction | Risk of bore damage from hammer impact |
| Blind Hole Compatible | Yes — puller bolt pulls pin from one side | No — requires through-hole for punch access |
| Material Options | 52100 Bearing Steel (HRC 60-64) | S45C, SKD11, 52100 |
| Cost | 15-20% premium over plain pins | Standard pricing |
| Best For | Mold plates requiring frequent maintenance | Permanent installations, through-hole plates |
What Is h7 Tolerance for Dowel Pins
The h7 tolerance designation defines the pin's diameter range relative to nominal size, per ISO 286:
- "h" = undersized: The pin diameter is at or below the nominal size (zero positive deviation). This means the pin slides into an H7 bore with a slight clearance or transition fit.
- "7" = tolerance grade: For a 10mm nominal pin, h7 means the diameter is 10.000mm to 9.985mm (tolerance zone = 0.015mm).
Why h7 for mold dowel pins? In injection molds, dowel pins must align plates to within 0.01-0.02mm while still being removable for maintenance. An h7 pin in an H7 bore provides this ideal balance: tight enough for repeatable alignment, loose enough for hand-push insertion and puller-bolt removal.
Comparison: m6 pins (interference fit) require press installation and are permanent — used when pins are never removed. h7 pins are the standard for molds that require regular maintenance access.
Application Scenarios
Mold Plate Alignment
Pain point: Cavity and core plates shift under injection pressure, causing parting line mismatch and flash on molded parts.
Why it fits: h7 dowel pins in H7 bores provide repeatable plate alignment to within 0.01mm. Two pins per plate pair define X-Y position; bolts provide only clamping force.
Recommended: 52100 Bearing Steel Tapped Dowel Pins, 2 per plate pair
Insert Alignment in Cavity Plates
Pain point: Cavity inserts shift during injection, causing dimensional variation in the molded part.
Why it fits: Small-diameter dowel pins (6-8mm) align cavity inserts to the pocket with sub-0.01mm repeatability. The tapped end allows insert removal without damaging the cavity plate.
Recommended: H7 Tapped Dowel Pins, 6-8mm diameter
Engineering Resources
Frequently Asked Questions
Why use 52100 bearing steel for dowel pins instead of standard carbon steel?+
How do I remove a tapped dowel pin?+
How many dowel pins do I need per plate pair?+
Need a Custom Quote?
Send your specifications and receive a quote. MOQ: 1 piece. Custom dimensions available.