Welcome to JARAWALA | 110+ Years old firm since 1914 | The First Choice of Indian Namkeen and Sweet Makers.
Welcome to JARAWALA | 110+ Years old firm since 1914 | The First Choice of Indian Namkeen and Sweet Makers.
Namkeen Machine Disc Sizing Chart: Outer Diameter, Bore & Hole Selection Guide
Engineering Reference • Luhar Girdher Devji & Sons (Est. 1914)
Namkeen Machine Disc Sizing Chart: Outer Diameter, Bore & Hole Selection Guide
A comprehensive engineering guide for snack food processors, industrial halwais, and farsan manufacturing units to select the exact outer diameter (OD), shaft bore, keyway, and CNC hole gauge for automatic and manual extruders.
1. Extrusion Physics: Why Precision Fitment Matters
In high-capacity commercial snack production, your namkeen extruder disc (jali) is the single critical orifice governing flow velocity, shear rate, dough temperature, and motor amperage. Selecting an improperly sized disc creates severe manufacturing bottlenecks:
- Excessive Hydraulic Backpressure: When hole perforation percentage is too low, cylinder backpressure spikes by up to 45%, straining hydraulic pumps, wearing gear teeth, and overheating dough (causing oil separation).
- Center Shaft Slippage: A center bore that is even 0.5mm oversized will chatter against the driving shaft under 150+ bar pressure, rounding out the keyway and damaging your main transmission.
- Non-Uniform Strand Breakage: Burred or rough punched holes create micro-drag on sev or ganthiya dough, causing curled, fractured strands instead of uniform, straight commercial lengths.
2. Master Sizing Matrix: Outer Diameter & Center Bore
Commercial namkeen extruders manufactured across India (Rajkot, Ahmedabad, Indore, Coimbatore, and Delhi) adhere to standardized disc sizing envelopes. Below is the master fitment matrix engineered and supplied by Jarawala:
Standard Commercial Extruder Disc Dimensions
Tolerances: ±0.05mm
| Outer Diameter (OD) | Center Bore ID | Standard Keyway | Disc Thickness | Machine Types |
|---|---|---|---|---|
| 5.0″ (127 mm) | 19 mm / 22 mm | 5 mm × 2.5 mm | 4.0 mm – 5.0 mm | Semi-Automatic & Tabletop Extruders |
| 6.0″ (152 mm) | 22 mm / 25.4 mm (1″) | 6 mm × 3.0 mm | 4.5 mm – 6.0 mm | Standard Commercial Rotary Machines (40–80 kg/hr) |
| 7.0″ (178 mm) | 25.4 mm / 28 mm | 8 mm × 3.5 mm | 5.0 mm – 6.5 mm | Heavy-Duty Continuous Extruders (80–140 kg/hr) |
| 8.0″ (203 mm) | 28 mm / 32 mm | 8 mm × 4.0 mm | 6.0 mm – 8.0 mm | Industrial High-Capacity Hydraulic Extruders (120–200 kg/hr) |
| 9.0″ & 10.0″ (Custom) | 32 mm – 42 mm | 10 mm × 4.5 mm | 8.0 mm – 10.0 mm | Tier-1 Automated Continuous Processing Lines |
3. Hole Gauge & Perforation Sizing for Core Snack Varieties
Different namkeen formulations—from ultra-fine nylon sev to thick, airy bhavnagari ganthiya—require exact perforation geometry to ensure smooth dough passage and optimal oil absorption during deep frying:
Snack-Specific Hole Geometry Reference
Material: SS 304 Food Grade
| Snack Variety | Hole Geometry | Exact Dimensions | Dough Viscosity | Ideal Frying Kadai Temp |
|---|---|---|---|---|
| Nylon Sev / Barik Sev | Round Micro-Punch | 0.8 mm – 1.0 mm | Medium-Soft (Pourable) | 175°C – 180°C (Instant 15s flash fry) |
| Ratlami Sev / Bhujia | Clover / Round Slit | 2.0 mm – 2.5 mm | Firm Spiced Besan | 170°C – 175°C |
| Bhavnagari Ganthiya | Oblong / Fluted Slit | 3.5 mm – 5.0 mm | Soft, Aerated Oil-Emulsified | 160°C – 165°C (Gentle puffing) |
| Papdi Ganthiya | Flat Ribbon Slit | 8.0 mm × 1.2 mm | Elastic Soda-Bi-Carb Dough | 165°C – 170°C |
| Murukku & Chakli | Star / Fluted Star (3 & 4 Point) | 3.0 mm – 4.0 mm | Rice & Urad Flour Stiff Dough | 165°C – 170°C |
| Boondi (Sweet / Salted) | Hemispherical Punch | 1.8 mm – 3.0 mm | Free-Flowing Liquid Batter | 180°C – 185°C |
Pro Engineering Tip • Caliper Measurement Protocol
When measuring your old disc for replacement, always measure using a digital vernier caliper across two perpendicular diameters to check for ovality. For the center bore, measure from the inside walls excluding the keyway cut-out. If your machine model lacks markings, our engineering team can match your fitment from a single high-resolution photograph and three caliper readings.
4. Frequently Asked Questions (FAQ)
Can Jarawala manufacture custom outer diameters or bore sizes?
Yes. In addition to our standard 5″ to 10″ inventory, Luhar Girdher Devji & Sons operates an advanced in-house CNC wire-cut and laser shop. We routinely manufacture custom ODs, non-standard keyways, splines, and proprietary multi-slit patterns to client blueprints.
How do CNC mirror-punched holes improve dough throughput?
Traditional mechanical punching leaves micro-burrs and tapered shear edges on the disc exit side, causing dough friction and frequent clogging. Jarawala CNC laser-punched discs feature mirror-smooth entry and exit chamfers that reduce frictional resistance by 30%, allowing continuous extrusion without burning or surging.
Which is better for high-production lines: SS 304 or Brass?
SS 304 is the industry gold standard for continuous high-acid, high-salt, and FSSAI-compliant automated manufacturing because it never corrodes, oxidizes, or reacts with spices. High-tensile brass is prized by traditional halwais for low coefficient of friction on soft ganthiya doughs.