The requirements for using square column fasteners(also known as square column clamps)mainly focus on component quality inspection and installation operation specifications.The core requirements,compiled from multiple sources,are as follows:
I.Quality Inspection Requirements Before Installation
Before using square column fasteners,a strict inspection of the components must be carried out to ensure they are in good condition:
Threaded parts:There should be no cracks,damage exceeding two threads,rust,or signs of elongation at the bottom of the final few threads.
Rod parts:There should be no bending,elongation,significant wear,or severe impact marks.
Screw head/nut edges:There should be no significant damage.A standard wrench should fit properly without slipping.
II.Technical Requirements for Installation Operation
1.Horizontal Installation Requirements
Square column fasteners must be installed horizontally to be effective.During installation,use a tape measure to mark a uniform height line,then install the four clamp plates in pairs,interlocking them on the same horizontal line.
2.Installation Spacing and Ground Clearance
Clearance of the first set from the ground:20–30 cm is recommended for easy subsequent removal.
Installation spacing:The spacing between each set of fasteners is generally 20–40 cm,which should be determined based on the column diameter and design requirements.
Spacing reference for columns of different diameters:
For columns with an 800 mm diameter:spacing at the bottom is 20 cm,which can gradually increase to 30–40 cm at the top.
For columns with a 600 mm diameter:spacing at the bottom is 20 cm,which can gradually increase to 50–60 cm at the top.
3.Fastening Operation Requirements
After inserting the wedge-shaped fixing pin,use a hammer to tap evenly to secure the wedge firmly.
The four clamp plates should be interlocked in pairs,with the bent edge aligned with the outer edge of the square column formwork.
Wedges should be stored centrally in woven bags to prevent loss.
4.Special Requirements for Tall Columns
When the column height exceeds 2.44 meters,the upper and lower connections of the formwork should be staggered to ensure the verticality and integrity of the square column.
III.General Requirements for Bolt-Type Fasteners
Bolts and nuts used in square column fasteners should also meet the following general requirements:
Screw-in depth(cast iron parts):Not less than 1.1 times the thread diameter.
Screw-in depth(steel parts):Not less than 0.8 times the thread diameter.
Exposed length of the bolt after tightening:2–3 threads exposed.
Margin for blind threaded holes:2–3 threads of margin left inside the hole.
Symmetrical tightening:When fixing components,bolts should be tightened evenly and in a symmetrical sequence to prevent distortion of the parts.
IV.Protection Requirements During Use
Anti-rust treatment:When using bolted connections for outdoor equipment parts,bolts should be coated with oil first.Bolts should ideally be inserted from top to bottom to prevent rainwater from entering and causing rust.
Anti-slip measures:Drive nails into the horizontal platform below the square column fasteners to prevent them from sliding down.
Base treatment:Seal the bottom of the square column formwork with concrete to facilitate easy formwork removal.
Safe operation:When installing square column fasteners,it is necessary to use scaffolding to provide safe conditions for high-altitude work.
V.Replacement and Repair Requirements
When replacing bolts and nuts,their specifications,models,strength grades,and other technical requirements should comply with the design drawings or match the original components.For bolted connections in critical areas,a torque wrench should be used as required by the design.Threaded parts of stainless steel bolt connections should be coated with a lubricant.
VI.Summary of Key Requirements
Installation direction:Must be installed horizontally.
Clearance of the first set from ground:20–30 cm.
Installation spacing:20–40 cm.
Exposed bolt threads after tightening:2–3 threads.
Allowable thread damage:No more than 2 threads.
Tall column handling(height>2.44 m):Staggered formwork installation.