Steel Sprue Bushings

Name: Steel Sprue Bushings — Bolt Fixing & Shoulder Types | Mold Components | Axiom Molds
Brand: Axiom Molds
Availability: InStock
Rating: 4.9 (128 reviews)

Complete range of steel sprue bushings — bolt fixing and shoulder types in 8–20 mm flange thicknesses, plus string eliminator, cooling circuit, extended nozzle, and environmentally friendly options.

Products — 16 Variants

Environmentally Friendly Sprue Bushings - Bolt Fixing, Flange Thickness 10

Environmentally Friendly Sprue Bushings - Bolt Fixing, Flange Thickness 10 mm

Environmentally Friendly Sprue Bushings - Flange Thickness 15 mm

Sprue Bushings - Sprue Port P3.5, Nozzle Touch SR 11, Bolt Fixing, Flange T

Sprue Bushings - Sprue Port P3.5, Nozzle Touch SR 11, Bolt Fixing, Flange Thickness 10 mm

Sprue Bushings - Bolt Fixing, Flange Thickness 10 mm

Sprue Bushings - String Eliminator, Bolt Fixing, Flange Thickness 10 mm

Sprue Bushings - Bolt Fixing, Flange Thickness 15 mm

Sprue Bushings - Bolt Fixing, Flange Thickness 20 mm

Sprue Bushings - Bolt Fixing, Flange Thickness 8 mm

Special Hexagon Socket Head Cap Screws for Sprue Bushing

Sprue Bushings - Old JIS A Type

Sprue Bushings - Flange Thickness 15 mm

Sprue Bushings - Old JIS B Type

Sprue Bushings with Locate Ring for Extended Nozzle

Sprue Bushings for Small Diameter Extended Nozzle

Sprue Bushings with Exclusive Bolts - Flange Thickness 10 mm

Sprue Bushings Around Cooling Circuit - Flange Thickness 10 mm, Stainless S

Sprue Bushings Around Cooling Circuit - Flange Thickness 10 mm, Stainless Steel Option

Compare Sprue Bushing Variants

16 variants span two mounting types, four flange thicknesses, and multiple special features:

Feature	Bolt Fixing (Standard)	Shoulder Type	String Eliminator	Cooling Circuit	Old JIS A/B
Mounting	Bolts through flange	Press-fit shoulder	Bolts through flange	Bolts through flange	Per legacy JIS spec
Flange Thickness	8, 10, 15, 20 mm	8, 10, 15 mm	10, 15 mm	Varies	Per JIS standard
Special Feature	None (standard)	Compact mounting	Anti-stringing geometry	Internal water cooling	Legacy compatibility
Material	S55C / SKD61	S55C / SKD61	SKD61	SKD61 / SUS	S55C
Best For	80% of standard molds	Compact mold designs	PA, PET, TPU (stringing resins)	Fast-cycle, high-temp molds	Replacing bushings in old molds

Recommendation: Start with bolt fixing, 10 mm flange (most common). Add string eliminator for stringing resins. Add cooling circuit for fast-cycle production. Use shoulder type only when bolt heads interfere with other components.

Mounting comparison: For detailed analysis, see our Bolt Fixing vs. Shoulder guide.

Step-by-Step Selection Guide

Four decisions narrow down your sprue bushing from 16 variants to 1:

Is this a new mold or replacing a bushing in an existing old JIS mold?

New mold → Current standard (bolt fixing or shoulder). Continue to Step 2.

Old JIS mold → Old JIS A or B type for dimensional compatibility.

Do bolt heads interfere with adjacent components?

No interference → Bolt fixing (most common, easiest to install/remove)

Yes, space is tight → Shoulder type (compact, no bolt heads)

Does your resin cause sprue stringing (PA, PET, TPU)?

Yes → String eliminator version

No → Standard version

Is cycle time limited by sprue cooling?

Yes → Cooling circuit version (internal water channels)

No → Standard (no cooling)

Flange sizing: Most molds use 10 mm flange. For guidance on other thicknesses, see our Flange Thickness Selection Guide.

About Steel Sprue Bushings

Steel sprue bushings are the most fundamental component of any cold runner injection mold. They create the primary resin channel from the injection machine nozzle into the mold. MISUMI offers the widest range of sprue bushings in the industry — 16 variants covering all mounting types, flange thicknesses, and special features.

S55C / SKD61 / SUSJIS Compatible16 Variants

Application Scenarios

Different production environments need different sprue bushing features:

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Standard Production Molds

General-purpose injection molds running commodity resins (ABS, PP, PE) at standard cycle times.

Standard bolt-fixing sprue bushing with 10 mm flange covers 80% of applications. No special features needed. Focus on matching SR and P to your injection machine nozzle.

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Stringing-Prone Resins (PA, PET, TPU)

Resins that create thin filaments (strings) between the nozzle and sprue when the mold opens.

String eliminator geometry creates a cold slug at the nozzle tip that breaks the string during mold opening. Eliminates the production nuisance of strings on parts.

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Fast-Cycle / High-Temperature Molds

Molds where cycle time is limited by sprue cooling, or processing high-temperature resins (PPS, PEEK, LCP).

Internal cooling circuit removes heat directly from the sprue area. Reduces sprue cooling time by 20-40%, shortening overall cycle time. Available in SKD61 or stainless steel.

Frequently Asked Questions

What flange thickness do I need for my mold plate?+

Flange thickness must match the counterbore depth in your mold's fixed plate where the locating ring sits. Most standard molds use 10 mm. Use 15 mm for deeper counterbores. 8 mm for compact molds. 20 mm for large molds needing additional rigidity.

What does a string eliminator feature do in a sprue bushing?+

String eliminator sprue bushings have a special nozzle touch geometry that creates a cold slug at the nozzle tip when the mold opens. This prevents the resin string that otherwise stretches between nozzle and sprue. Essential for PA, PET, TPU.

Are old JIS A/B type sprue bushings still dimensionally compatible with new molds?+

Old JIS A and B types follow legacy JIS standard dimensions. They are still available for replacement in existing molds built to these standards. For new mold designs, use current standard bolt-fixing or shoulder types.

What is the benefit of sprue bushings with integrated cooling circuits?+

Cooling circuit sprue bushings have internal water channels that remove heat directly from the sprue area. This reduces cooling time for the sprue (often the thickest section), shortens cycle time, and prevents nozzle tip degradation.

Can I get sprue bushings in stainless steel for corrosive resins?+

Yes. MISUMI offers cooling circuit type sprue bushings with stainless steel options. Stainless resists corrosion from halogenated flame retardants, acidic resins (PVC), and humid environments.

Engineering Resources

Comparison

Need a Custom Quote?

Specify your nozzle SR, sprue port diameter (P), flange thickness, mounting type (bolt/shoulder), and any special features (string eliminator, cooling circuit). Custom SR and P dimensions available.

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✓ MOQ 1 piece✓ 16 variants in stock✓ Custom SR/P available