JB/T 7334 Hand Chain Hoist Standard Guide
JB/T 7334-2016, the industry standard for hand chain hoists, is the governing technical document that defines the product's type designations, basic parameters, technical requirements, test methods, inspection rules, and marking, packaging, transport, and storage specifications. It applies to hand chain hoists with a rated lifting capacity of 0.5t to 40t and serves as the primary reference for design & manufacturing, factory acceptance testing, and product selection.
Also known as a "chain block" or "ratchet lever hoist," the hand chain hoist is one of the most common types of light-duty manual lifting equipment. The operator pulls the hand chain to rotate the hand chain wheel, which drives the load chain sprocket through a gear reduction mechanism to lift the load. JB/T 7334-2016 is the current industry standard governing this product, providing comprehensive requirements for mechanical performance, safety indicators, and inspection rules. Thanks to their simple construction, independence from power supplies, and low-maintenance requirements, hand chain hoists are widely used in factory workshops, warehousing and logistics, construction sites, and equipment installation applications.
Unlike electric hoists, hand chain hoists are not restricted by power supply availability, making them suitable for lifting operations in locations without electricity and in explosion-proof environments. Although their lifting speed is relatively slow (typically 0.02–0.05 m/s), they offer precise positioning and smooth operation. Kelude Heavy Industry manufactures a full range of hand chain hoists covering 0.5t to 20t, with core components forged from alloy steel and heat-treated. Every unit undergoes a 1.25-times dynamic load test before leaving the factory.
Working Principle and Core Component Structure
The drive system of a hand chain hoist consists of five main components: the hand chain, hand chain wheel, gear reduction mechanism, load chain sprocket, and load chain. When the operator pulls the hand chain, the hand chain wheel rotates, and the torque is amplified through multiple stages of gear reduction before being transmitted to the load chain sprocket, which raises or lowers the load via the load chain and hook. The standard requires that the gear reduction ratio be properly designed according to the rated lifting capacity to ensure the hand pull force does not exceed 360 N (approximately 36 kgf), allowing a single operator to handle even the largest tonnage units.
The load chain is one of the most critical load-bearing components of a hand chain hoist. The standard mandates the use of high-strength calibrated chain conforming to GB/T 5802, with common diameters ranging from φ6mm to φ10mm. The chain material must be 20Mn2 alloy steel or an equivalent higher grade, heat-treated through quenching and tempering to achieve a surface hardness of HRC42–50. The standard explicitly requires that the minimum breaking force of the chain be no less than 4 times the rated lifting capacity, and that the chain must not exhibit permanent deformation when subjected to 1.5 times the rated load.
The braking system employs a ratchet-and-friction-lining brake, consisting of a ratchet, pawl, and brake housing. Its working principle is as follows: during hoisting, the pawl engages with the ratchet under spring tension, preventing the load from free-falling; during lowering, the operator pulls the hand chain in the reverse direction to disengage the pawl, allowing the load to descend under its own weight. The standard specifies that the brake slip distance must not exceed one chain link per minute under 1.25 times the rated load.
| Gearnumber of stages | Reduction Ratiorange | applicable tonnage | hand pull force(N) | features |
|---|---|---|---|---|
| single-stage Gear | 1:5~1:8 | 0.5t~2t | ≤280 | simple construction, compact size |
| two-stage Gear | 1:20~1:40 | 1t~5t | ≤320 | Torquefull amplification, good overall performance |
| three-stage Gear | 1:60~1:100 | 5t~20t | ≤360 | large Reduction Ratio, easy operationlarge tonnage |
| planetary gear | 1:30~1:80 | 10t~40t | ≤360 | compact structure, high load capacity |
Load Capacity & Model Selection
JB/T 7334-2016 specifies thirteen rated lifting capacity ratings for hand chain hoists: 0.5t, 1t, 1.6t, 2t, 2.5t, 3.2t, 5t, 8t, 10t, 16t, 20t, 32t, and 40t. Units from 0.5t to 5t are classified as light-duty, primarily intended for routine maintenance and general hoisting tasks. The 10t to 20t range serves as medium-duty, suited for equipment installation and production line assembly. Heavy-duty models from 32t to 40t are designed for lifting and moving large-scale equipment. For hoists rated above 10t, dual-chain or four-chain configurations are commonly employed to enhance safety and reliability by increasing the number of load-bearing chains.
Standard lifting heights are tiered by capacity: 2.5m or 3m for 0.5t–2t models, and 3m for 3.2t–40t models. Custom non-standard lift heights can be accommodated upon request; however, extending the chain adds dead weight that increases the manual pull force required during operation. As a selection guideline, it is recommended to choose a hoist with a rated capacity 1.25 to 1.5 times the actual load weight to ensure an adequate safety margin.
For demanding, high-frequency applications, select a hoist with a work duty classification of at least M4. The duty level is determined per the classification method outlined in JB/T 7334, based on average daily operating time and the load spectrum factor. Hoists rated for higher duty cycles incorporate upgraded gear materials, premium bearings, and refined heat treatment processes, delivering extended service life.
Material & Heat Treatment Requirements for Key Components
The hook is the most critical load-bearing component of a hand chain hoist. Standards require it to be forged from 20# steel or 20Cr steel, followed by normalizing. The hook throat undergoes surface hardening to HRC38–45. Every finished hook must pass 100% Magnetic Particle Inspection (MPI) or Ultrasonic Testing (UT), with no cracks, folds, scars, or other defects permitted. If the hook opening deforms by more than 10% of its original dimension during service, the hook must be immediately taken out of service and replaced.
Gears must be manufactured from alloy structural steel such as 40Cr or 20CrMnTi. After carburizing and quenching, the tooth surface hardness must reach HRC55–62, with a core hardness of HRC30–45. The case depth is determined by the gear module, typically 0.8–1.2mm. Gear accuracy must meet or exceed Grade 8 per GB/T 10095. Prior to assembly, all gears must undergo meshing inspection, with contact patterns covering no less than 40% along the tooth height and 50% along the tooth length.
| Inspectionitem | Standard Indicator | Testconditions |
|---|---|---|
| No-Load Test | smooth running, no jamming, no Abnormal noise | full-stroke reciprocation≥3cycles |
| Dynamic Load Test | 1.1times rated load, full-range lifting and lowering≥10cycles | all mechanisms operate normally |
| brake slip distance | ≤1chain links/min | 1.25times rated load, Hoisting / Lifting300mmat rest after |
| Static load test | 1.5times rated load, continuous10min | no permanent Deformation, no Crack |
| chaintotal elongation | ≤original length3% | 1.25times rated load,500measured after cycles |
| Gearmeshing | Contact pattern≥40%(high)/50%(total elongation) | dye penetrant inspection |
Frequently Asked Questions
Q: What basic parameters and application scope does the JB/T 7334-2016 standard define for hand chain hoists?
A: JB/T 7334-2016 specifies a rated lifting capacity range of 0.5t to 40t across thirteen models, with standard lifting heights of 2.5m or 3m. The standard applies to hand chain hoists that use a manually operated chain loop to drive the load chain sprocket through a gear reduction mechanism, covering full technical requirements from Design & Manufacturing through Factory Acceptance Test.
Q: How do I select the right hand chain hoist capacity for my specific operating conditions?
A: The key selection parameter is the actual weight of the load to be lifted. We recommend sizing the rated lifting capacity at 1.25 to 1.5 times the calculated load. For frequent production use, choose a hoist rated at Work Duty M4 or higher, and pay attention to gear material (40Cr/20CrMnTi) and heat treatment process (Carburizing and Quenching, HRC55~62). For large tonnage applications above 10t, dual-chain or four-chain configurations are recommended to provide additional safety redundancy. Also verify that the lifting height matches your workspace clearance.
Q: What is the recommended inspection interval and what are the key inspection items for hand chain hoists?
A: JB/T 7334 requires a comprehensive periodic inspection once a year, along with a visual inspection before each use. Core inspection items include: hook opening deformation measurement (≤10%), total elongation of the load chain (≤3%), Brake Slippage Test (≤1 chain link per minute), and gear Contact pattern check. A hoist that has been out of service for an extended period must pass a full inspection and a 1.25x Dynamic Load Test before being returned to service.
Q: How can safe operation of hand chain hoists be ensured on construction sites and during equipment installation?
A: Safe operation hinges on the following: before lifting, check that the hook anti-drop device is intact, the chain is free of kinks or twists, and both hooks are vertically aligned under load. Never pull at an angle or overload the hoist. When multiple operators pull the hand chain, coordinate the rhythm. Never allow personnel to stand beneath a suspended load. After use, remove the hoist and store it properly to avoid prolonged chain stress. Kelude hoists come standard with Overload Protection and a 360° Swivel Hook for enhanced operational safety.
Standard basis: JB/T 7334-2016 "Hand Chain Hoists" | Technical Department
