Manufacturing Design Guides

Get practical insights from TOPWELL’s engineering team to optimize your product designs for injection molding, CNC machining, mold manufacturing, and assembly.

Injection Mold

1.Mold Steel Selection

Low volume general parts: P20,718H
High gloss / textured & corrosive resin: S136, NAK80
High volume & glass-filled plastic: FDAC, H13
Steel option adjustable by annual quantity, plastic property and cosmetic requirement.

2.Tiered Machining Tolerance

Standard Tolerance: Cavity ±0.02~0.03mm, mold base ±0.05mm
Typical Achievable Tolerance: Precision cavity ±0.008~0.015mm
Tight Tolerance Available Upon Request with extra quotation

3.Machining & Assembly Spec

Critical mold base surfaces precision ground for flatness and squareness
Process flow: rough CNC → heat treatment → grinding / EDM / fine machining
Standard clearance for slider & lifter:0.008~0.02mm, adjustable for high temp plastic
Cooling channels close to part geometry, away from thin cosmetic wall

4.Trial & Surface Finish

Tight parting line shut-off, smooth ejection without jam
Verify dimension, shrinkage and appearance before mass production & sample lock
Polish, texture, nitriding customized per customer’s drawing

Stamping Die

1.Mold Steel Selection

General blanking & bending: Cr12
High-volume progressive die: SKD11, DC53
Low-cost simple tool: tempered 45# steel
Material modified according to sheet material and production runs.

2.Tiered Machining Tolerance

Standard Tolerance: cutting cavity ±0.02~0.04mm, mold base ±0.06mm
Typical Achievable Tolerance: precision progressive die ±0.01~0.02mm
Tight Tolerance Available Upon Request

3.Machining & Assembly Spec

Punch & die insert heat treated & ground to avoid edge chipping
Bend insert radius matched with part design, clearance set by sheet thickness
Stripper plate clearance controlled to prevent part scratching

4.Trial Stamping

First article inspection on dimension, burr and flatness
Master sample locked after stable mass trial

Die Casting Mold

1.Mold Steel Selection

Common aluminum die casting: H13,8407
Small batch zinc alloy casting: FDAC, SKD61
Steel grade changed based on casting alloy and production volume.

2.Tiered Machining Tolerance

Standard Tolerance: cavity ±0.03~0.05mm, mold base ±0.06mm
Typical Achievable Tolerance: precision casting cavity ±0.015~0.025mm
Tight Tolerance Available Upon Request

3.Machining & Assembly Spec

Stress relief temper after heat treatment to reduce thermal deformation
Optimize runner & overflow layout according to component structure
Dense cooling layout to handle high pressure & high temperature casting

4.Trial Casting

Test casting to eliminate porosity, sink mark and cold shut defects
Gate revision until qualified for mass production

Injection Molding

1) Mold Steel Selection

General blanking & bending: Cr12
High-volume progressive die: SKD11, DC53
Low-cost simple tool: tempered 45# steel
Material modified according to sheet material and production runs.

2) Tiered Machining Tolerance

Standard Tolerance: cutting cavity ±0.02~0.04mm, mold base ±0.06mm
Typical Achievable Tolerance: precision progressive die ±0.01~0.02mm
Tight Tolerance Available Upon Request

3) Machining & Assembly Spec

Punch & die insert heat treated & ground to avoid edge chipping
Bend insert radius matched with part design, clearance set by sheet thickness
Stripper plate clearance controlled to prevent part scratching

4) Trial Stamping

First article inspection on dimension, burr and flatness
Master sample locked after stable mass trial

Metal stamping

1.DFM Design Standard

Suggested minimum bend radius ≥ material thickness, zero bend radius not recommended for thin sheet
Standard minimum hole ≥ sheet thickness, tiny holes need pre-production check
Keep safe clearance between bend line and holes; optimize long thin cantilever structure

2.Tiered Tolerance

Standard Tolerance: ±0.08~±0.15mm
Typical Achievable Tolerance: ±0.03~±0.06mm
Tight Tolerance Available Upon Request
Regular flatness deviation ≤0.2mm, tight flatness upon special quotation

3.Production & Appearance Notes

Small fillet on sharp corner to reduce burr
Edge modification available for plating-grade parts

IML / IMD

1.DFM Design Standard

Suggested minimum wall:0.4~0.6mm; radius & draft applied for thin pins
0.08~0.15mm bonding gap reserved for overmolding structure
Reinforcement design recommended for extra long thin ribs

2.Tiered Tolerance

Standard Tolerance: ±0.10~±0.18mm
Typical Achievable Tolerance: ±0.05~±0.08mm
Tight Tolerance Available Upon Request

3.Production & Appearance Notes

Rounded seal groove helps control flash
Avoid ultra-thin wall on poor venting position

Silicone & Rubber Molding

1.DFM Design Standard

Min silicone wall:0.4~0.6mm, full radius + draft for thin pins
0.08~0.15mm bonding gap reserved for overmolding structure
Reinforcement on extra long thin rib against curing deformation

2.Dimensional Tolerance

General silicone part: ±0.10~±0.18mm
Precision sealing component: ±0.05~±0.08mm

3.Production & Appearance Notes

Rounded seal groove to reduce excess flash
Avoid ultra-thin wall at poor venting area to prevent bubble & short shot