# Professional Guide to Agricultural Machinery Parts Selection and Quality Identification

Professional Guide to Agricultural Machinery Parts Selection and Quality Identification I. Classification and Characteristics of Common Agricultural Machinery Parts (1) Core Components of the Power System Agricultural Tires — Genuine product features: Complete sidewall markings (including ply rating, cord material, and production batch number); uniform tread pattern depth (new tires ≥8mm); good rubber elasticity of the carcass (rebound rate ≥80%). Inferior performance: Blurred or missing markings; sidewall thickness variation >1.5mm; rubber aging cracks. Threaded Fasteners — Quality standards: Surface finish Ra≤3.2μm; thread go/no-go gauge inspection passed; tensile strength ≥400MPa. Testing methods: Spin-fit test with standard parts (should be free of jamming); torque test (reaching ≥90% of the rated value). (2) Key Components of the Transmission System Gear Sets — High-quality features: Tooth surface hardness HRC58-62; involute tooth profile accuracy grade 7 or above; carburized layer depth 0.8-1.2mm. Inspection points: Magnetic particle inspection for cracks; red lead powder mesh test (contact area ≥75%). Transmission V-Belts — Genuine product indicators: Cord arrangement density ≥60 cords/10cm; rubber tensile strength ≥15MPa; service life ≥1000 hours. Inferior characteristics: Cross-section dimension deviation >1mm; belt body delamination. (3) Core Components of the Engine Piston Ring Sets — Quality requirements: End gap 0.3-0.5mm; light leakage ≤30°; surface chrome plating thickness 0.1-0.15mm. Testing methods: Feeler gauge measurement of ring groove clearance; light transmission inspection for roundness. Filter Systems — Genuine product standards: Filtration precision 10-20μm (diesel); initial resistance ≤2.5kPa; filter paper weight ≥100g/m². Counterfeit characteristics: Loose end cap sealing; uneven filter media thickness. II. Three-Dimensional Quality Identification Testing Method (1) Visual Inspection System Surface quality inspection: Machining texture should be uniform and continuous; plating quality free of bubbles and peeling; markings clear (including material, specifications, etc.). Tool preparation: Digital caliper (accuracy 0.01mm); thread gauge (with go/no-go set). Key dimensions: Bearing inner diameter tolerance ±0.005mm; gear module error ≤0.02. (2) Auditory Testing Method Tapping test: Castings should produce a crisp sound; welded parts should have no dull or cracked sound. Operation test: Bearings should have no abnormal whining; gear mesh sound should be uniform. (3) Tactile Inspection Points Surface texture: Finished surfaces Ra≤1.6μm; cast surfaces free of sharp protrusions. Fit test: Shaft-hole fit H7/g6 grade is preferred; threaded fit should allow manual insertion without obstruction. III. Recommended Professional Testing Tools | Testing Item | Recommended Tool | Accuracy Requirement | | Dimension measurement | Digital micrometer | 0.001mm | | Hardness testing | Rockwell hardness tester | ±1HRC | | Form and position tolerance | Coordinate measuring machine | 0.005mm | | Material analysis | Spectrometer | 0.01% | IV. Procurement Pitfall Avoidance Guide Channel selection: Prioritize manufacturer-authorized distributors; on e-commerce platforms, only purchase from brand official stores. Price warning: Be cautious of prices 30% below market value; request proof of tax payment. Document verification: Three mandatory certificates required (product qualification certificate, quality guarantee letter, and test report). After-sales support: Warranty period of no less than 1 year; return and exchange policy allowing returns within 15 days. V. Parts Usage Recommendations Break-in period management: New gear sets should run at light load for 50 hours; new piston rings should have speed controlled for the first 20 hours. Maintenance cycle: Lubricate key components every 100 hours; check wear amount quarterly. Scrap standards: Gear tooth thickness wear >15%; bearing clearance >0.1mm; belt cracks >3 per 10cm. Through systematic quality identification methods and standardized procurement procedures, the safety and cost-effectiveness of agricultural machinery parts usage can be ensured. It is recommended to establish parts usage records, documenting replacement cycles and performance, to provide data support for future procurement.