Nuts are indispensable standard components in mechanical connections, achieving fastening functions through cooperation with bolts. Their manufacturing centers on lathe turning as the core process, combined with thread forming technology to ensure precision and strength. The following provides a detailed explanation across four dimensions: manufacturing processes, quality control, application scenarios, and development trends:

I. Core Lathe Machining Processes for Nuts
1. Blank Preparation
Material Selection:
Carbon Steel (Q235, 45#): Low cost, suitable for general mechanical connections.
Stainless Steel (304, 316): Corrosion-resistant, used in food and chemical industries.
Copper Alloy (H62): Excellent conductivity, used for electrical connections.
Alloy Steel (40Cr, 35CrMo): High strength, used in heavy machinery.
Blank Formats:
Hexagonal bar stock: Direct external turning, suitable for small-batch production.
Forged round bar: Preformed hexagonal shape reduces turning allowance, ideal for mass production.

2. Turning Process Flow
Step 1: External Turning
Equipment: Conventional lathe or CNC lathe.
Parameters:
Rough turning: Cutting depth 2-3mm, feed rate 0.2-0.3mm/r, spindle speed 500-800r/min.
Finish turning: Cutting depth 0.1-0.2mm, feed rate 0.05-0.1mm/r, spindle speed 1000-1500r/min.
Accuracy: Outer diameter tolerance ±0.05mm, surface roughness Ra ≤3.2μm.
Step 2: Face Turning
Tool: 45° face turning tool.
Control points: Ensure face perpendicularity to axis ≤0.02mm to prevent thread skew.
Step 3: Bore Turning (Boring)
Equipment: Boring bar or floating boring tool.
Parameters:
Rough boring: Cutting depth 1-2mm, feed rate 0.1-0.2mm/rev.
Finish boring: Cutting depth 0.05-0.1mm, feed rate 0.02-0.05mm/rev.
Accuracy: Bore diameter tolerance H8-H9, surface roughness Ra ≤ 1.6μm.

3. Thread Machining Methods
Method 1: Thread Turning (Cutting Method)
Tool: Thread turning tool (high-speed steel or cemented carbide).
Parameters:
Pitch ≤ 1mm: Spindle speed 800-1200 r/min, Feed rate = Pitch.
Pitch 1-3mm: Spindle speed 500-800 r/min, Feed rate = Pitch.
Accuracy: Thread tolerance 6g (external threads)/6H (internal threads), surface roughness Ra ≤ 3.2μm.
Method 2: Thread Rolling (Non-Cutting Method)
Tooling: Thread rolling dies.
Advantages: High material utilization (30% material savings), 20%-30% increase in surface hardness, enhanced fatigue resistance.
Applications: Mass production of standard nuts (M6-M24).