From Raw Brass to Precision-Engineered Inserts
Every Chetna Industries brass insert goes through a meticulously controlled manufacturing pipeline — ensuring dimensional accuracy, surface quality, and mechanical performance meet the highest global standards.
Our Manufacturing Philosophy
At Chetna Industries, manufacturing is not just about turning brass on a lathe — it's a comprehensive, ISO Certified quality-driven process that combines advanced CNC technology, skilled craftsmanship, and rigorous quality control at every stage. Our process is designed to deliver zero-defect CNC brass inserts consistently, whether producing a prototype run of 500 pieces or a mass production order of millions.
We use modern multi-axis CNC turning centers and Swiss-type automatic lathes that allow us to produce complex geometries with tolerances as tight as ±0.005mm. Our manufacturing workflow includes automated bar feeding, in-process gauging, and SPC monitoring to ensure every insert meets specification.
Our 8-Step Manufacturing Process
Raw Material Selection & Testing
We source high-grade free-machining brass rods (CDA C36000, C38500, and lead-free C69300) from certified mills. Every incoming batch undergoes chemical composition analysis, hardness testing, and dimensional verification before entering production. Only materials meeting our strict acceptance criteria proceed to the manufacturing floor.
CNC Turning & Primary Machining
Brass rods are loaded into automatic bar-feeding CNC lathes where the primary turning operations create the basic insert profile — outer diameter, length, chamfers, and overall geometry. Multi-axis CNC turning centers allow us to complete complex profiles in a single setup, minimizing handling and maximizing accuracy.
Diamond Knurling
External knurl patterns are applied using precision knurling tools. We offer straight knurl, diamond knurl, and helical knurl patterns in various pitches. The knurl pattern is critical — it determines the insert's pull-out resistance and torque-out resistance when installed in plastic. Our knurling parameters are optimized for each specific application and plastic material type.
Internal Thread Cutting
Internal threads are cut using high-precision thread-cutting tools or thread-forming taps. We support Metric (M2-M12), UNC, UNF, BSP, and BSW thread standards. Thread quality is verified against Go/No-Go thread gauges after every production run. Thread depth, pitch diameter, and major/minor diameters are all controlled to applicable standards.
Secondary Operations
Depending on the insert design, secondary operations may include slotting (for expansion inserts), cross-drilling, hex milling, counter-boring, or flat machining. These operations are performed on dedicated secondary operation machines with CNC precision to maintain concentricity and perpendicularity with the primary features.
Deburring & Surface Finishing
All machined inserts go through tumbling or vibratory deburring to remove machining burrs and sharp edges. This ensures safe handling and clean installation. Surface finishing options include natural brass, nickel plating, tin plating, or custom coatings based on application requirements and customer specifications.
Quality Inspection & Testing
Every production lot undergoes comprehensive quality inspection in our dedicated quality lab. Inspections include dimensional measurement (digital calipers, micrometers, and optical comparators), thread gauging (Go/No-Go), surface roughness measurement, hardness testing, and visual inspection under magnification. We follow AQL sampling plans as agreed with each customer.
Packaging & Global Shipping
Approved inserts are carefully counted, weighed, and packed in anti-tarnish bags within corrugated cartons. Proper labeling includes part number, quantity, lot number, and inspection certificate reference. We ship worldwide via sea freight, air freight, or express courier — supporting FOB, CIF, and DDP Incoterms for seamless international delivery.
Advanced Manufacturing Technology
Multi-Axis CNC Turning Centers
High-precision CNC lathes with live tooling capability, allowing complex operations including turning, milling, drilling, and threading in a single setup. Enables tolerances of ±0.005mm on critical dimensions.
Swiss-Type Automatic Lathes
Sliding-headstock lathes optimized for small-diameter brass inserts with exceptional concentricity. Ideal for high-volume production of inserts from M2 to M6 with minimal material waste.
Precision Inspection Equipment
Digital micrometers, optical comparators, profile projectors, surface roughness testers, and Go/No-Go thread gauges for comprehensive dimensional and thread quality verification.
Secondary Operation Machines
Dedicated machines for slotting, cross-drilling, hex milling, and tapping. CNC-controlled for consistent accuracy across high-volume production runs.
Diamond Knurling Equipment
Precision knurling machines capable of producing diamond, straight, and multi-ring patterns with controlled depth and pitch. Ensures maximum pull-out resistance and anti-rotation performance in molded assemblies.
Surface Treatment Line
Complete electroplating and finishing line for nickel plating, chrome plating, tin plating, and natural brass polishing. Automated bath controls ensure uniform coating thickness and corrosion resistance.