This standard specifies the tree species, size, material index and inspection method of shaft timber. This standard applies to shaft timber used in mines. GB 4820-1995 Shaft timber GB4820-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Sawn timber for shaft lifting guideSubject content and scope of application
This standard specifies the tree species, dimensions, material indicators and inspection methods of shaft timber. This standard applies to shaft timber for mine shafts. Reference standards
GB4822
3 Technical requirements
3.1 Tree species
Sawn timber volume table
Sawn timber inspection
Korean pine, Scotch pine, spruce, Yunnan pine, Armand pine, Guangdong pine. Note: Other tree species can be agreed upon by both the supplier and the buyer. 3.2 Dimensions
3.2.1 Length: 6,8m.
3.2.2 Width, thickness: in mm. 210×210
270×270
240×240
300×300
Note: The above dimensions can be selected by users according to actual needs. If other dimensions are required, they shall be agreed upon by both parties. 3.2.3 Tolerance
3.2.3.1 Length allowed: cm.
3.2.3.2 Width and thickness allowed: mm.
3.3 Material indicators are shown in the table below.
Defect name
Live knot, dead knot
Maximum size shall not exceed the width of the material
Within the entire length of the material
The maximum number of wormholes within 1m shall not exceed the State Administration of Technical Supervision Approved on December 8, 1995
GB4820—1995www.bzxz.net
Replaced GB4820-—84
Allowable limit
Not allowed
Implemented on July 1, 1996
Defect name
Crack, skinning
Length shall not exceed the length of the material
Through the end face
GB 4820-1995
The maximum notch size shall not exceed (not allowed for the entire length of the timber) The maximum bend arch height shall not exceed the horizontal length of the inner bend. Measurement methods and volume measurement
Dimensional measurement and inspection and evaluation shall be carried out in accordance with the provisions of GB4822 sawn timber inspection. Volume measurement shall be carried out in accordance with the provisions of GB449.
Additional notes:
This standard is proposed by the Ministry of Forestry of the People's Republic of China. This standard is under the jurisdiction of the China Timber Standardization Technical Committee. This standard was drafted by the Sawn Timber Standard Technical Committee. The main drafters of this standard are Zhou Shimian, Wang Xinmin, Wu Wanrong, Wang Wensheng, and Zhou Qiong. 280
Allowed limit
Not allowed
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.