Product Tutorials: Threaded Inserts

What They Are

Single piece assemblies combining a nut and rivet which provide high quality, load bearing female threads in thin sheet materials, box sections and tubing. They are ideal for placing in painted/coated materials as they do not damage the surface, which avoids re-work and wastage. Once installed, they are extremely resistant to pull-out and push-out pressures.

• Blind sided assembly
• Purely mechanical fastening
• Designed for rapid rate of installation
• Designed for automation
• Forms a permanent fixture in material
• Multi-functional fastener
• Suitable for a wide range of installation tools

Threaded inserts consist of 4 features: A. Head (a.k.a. Flange) B. Body (a.k.a. Shank) C. Splines D. Threads

How They Work

1. By hand, the threaded insert is turned onto the mandrel of the tool for a couple of threads to prevent cross threading.
2. The threaded insert is pushed axially toward the tool head activating the tool motor, which spins the mandrel into the remainder of the insert. This draws the flange of the threaded insert firmly into place against the tool nose assembly.
3. The insert, now located on the tool mandrel, is placed in the application hole and the tool is actuated. The mandrel is pulled axially toward the rear of the tool exerting a pulling force on the threads of the insert, which collapses and sets the insert.
4. The mandrel reaches the adjustable stop in the rear of the tool, which causes the mandrel to reverse its spin out of the threaded insert. The threaded insert is now installed.

Insert Styles

	Expanding Insert Single piece which breaks into two pieces during installation. The lower threaded section draws up inside the upper sleeve section, causing the sleeve to expand 360o thus swaging the insert into the hole. Used in sheet metals over 0.030” thick up to and including blind holes. Nutsert®, Supersert®.
	Bubbling Insert When set, they form a bubble on the backside of the application, trapping the material between its flange and the backside bubble. Must protrude through the backside to upset and form the bubble. Closed End, DK, DL, Eurosert®, Hexsert®, LF TSN®, Squaresert™, TSN®.

Design Features

Example Images	Design Features	Design Benefits	Typical Applications
	Splined Body	Improves torque-to-turn by up to 50% compared to plain body inserts Improved electrical continuity in sheet metal fixings	Soft materials such as aluminium, magnesium, plastics, composites and wood Earthing points in electrical assemblies
	Hexagonal Body	Improves torque-to-turn in metallic sheets by up to 200% compared to plain body inserts	Automotive chassis components requiring high resistance to turning under vibrating loads Where high bolt removal torque is required during servicing (e.g. switchgear cabinets) Thermal applications prone to high expansion and contraction in parent material
	Square Body	Improves torque-to-turn in metallic sheets by up to 350% compared to plain body inserts Increased punch life compared to hexagonal geometries	Automotive body mountings requiring maximum turning resistance Soft material constructions, particularly for plastics, composites and soft sheet metals
	Large Flange	Provides large load bearing surface Reinforces hole, preventing push through Potential to use flange as a spacer Can be used with underhead seal (e.g. Rimlex)	Load bearing applications in thin sheet and soft material applications Mountings where high push-out resistance is required (e.g. adjustable foot mountings)
	Low Profile	Near flush installation and clamp up	Flush fitting, thin sheet, low load bearing applications (e.g. domestic appliances and coach building)
	Countersunk	Flush installation and secure clamp up	Flush fitting, thin sheet, low load bearing applications (e.g. domestic appliances and coach building)
	Closed End	Prevents ingress of dirt and fluids into thread Prevents ingress of water and foreign bodies into electrical circuits	Electrical assemblies to prevent foreign bodies being inserted through open thread Load bearing sections to avoid thread exposure With underhead seal (Rimlex) to prevent ingress of fluids and dirt into protected environment (e.g. fuel tank)
	Reduced Tail End Diameter	Ease of hole entry Particularly suited for automation	Automated feed systems Rapid manual assembly
	Increased Thread Strength	Improves the maximum torque capability by typically 100% compared to standard Hexsert® No risk of thread-stripping insert, avoiding expensive and time consuming re-work Potential to downsize insert and screw diameter for a given joint clamp load	Structural automotive fixings into closed aluminium extrusions and hydro-formed steel tubes High strength threads into thin, hardened steel pressings unsuited to welding Any application where routine screw removal and re-tightening without torque control is likely

Inserts

Insert Family	Material	Key Features
	Aluminum Steel	DK Splined body improves torque-to-turn & improves electrical continuity in sheet metal fixings. Low profile for near flush installation and clamp up. Reduced tail diameter for ease of hole entry. Particularly suited for automation.
	Aluminum Steel	DL Splined body improves torque-to-turn & improves electrical continuity in sheet metal fixings. Large flange provides large load bearing surface, reinforces hole, prevents push through. Reduced tail diameter for ease of hole entry. Particularly suited for automation.
	Steel	Eurosert® Splined body improves torque-to-turn & improves electrical continuity in sheet metal fixings. Large flange option provides large load bearing surface, reinforces hole, prevents push through. Low profile option for near flush installation and clamp up. Reduced tail diameter for ease of hole entry. Particularly suited for automation.
	Steel	Hexsert® Hex body shape improves torque-to-turn in metallic sheets by up to 200% compared to plain body inserts. Large flange option provides large load bearing surface, reinforces hole, prevents push through. Low profile option for near flush installation and clamp up. Reduced tail diameter for ease of hole entry. Particularly suited for automation. High strength option improves the maximum torque capability by typically 100% compared to standard Hexsert®. High strength option no risk of thread-stripping insert, avoiding expensive and time consuming re-work.
	Steel	High Strength Hexsert® Exceptional torque capability. High speed assembly. Provides high-strength threads in thin materials starting at 0.5mm. Increased thread strength. If excessive torque is applied, the screw shank should fail before the insert, avoiding over-tightening problems such as thread stripping and expensive rework. Installed and retrofitted with standard Avdel® handtools, as well as multi-head and auto-feed robotic systems.
	Steel	Nutsert® Expanding body style allows installation in blind holes. Low profile flange for near flush installation and clamp up. Reduced rear sheet protrusion.
	Steel	Squaresert® Square body improves torque-to-turn & punch life compared to hexagonal geometries. Large flange option provides large load bearing surface reinforces hole, prevents push through.
	Steel	Supersert® Expanding body style allows installation in blind holes. Low profile flange for near flush installation and clamp up. Reduced rear sheet protrusion. Greater mechanical performance than Nutsert®.
	Aluminum Steel Stainless	TSN® Low profile option for near flush installation and clamp up. Reduced tail diameter for ease of hole entry. Particularly suited for automation.
	Steel	VERSA-NUT® Specially designed for use in soft materials, plastics and composites Quickly installed by using simple handtools (less than 3 seconds) Only require blind side access Extra large blind side bearing area after placing Higher pull out and torque-to-turn resistance Less radial loading of holes in brittle materials Less risk of cracking and de-lamination of composites Up to twice the grip range of standard blind inserts Enables a designer to reduce the size or number of fasteners in an assembly Covers large variations of thicknesses

Insert Selection

Thread Size Avdel® threaded inserts range from M3 to M12 thread sizes dependent upon the insert. Imperial threads are also available. Grip Range The threaded insert should be selected to ensure that the thicknesses of the parent material(s) falls within the grip range. Hole Size This is specified on the relevant technical data page for the insert. Allowance for coating the parent material should be made to avoid an undersized hole. Torque-to-Turn Resistance is dependent upon the body shape and increases in the series: round, splined, hexagonal and square. Special Features Additional features such as low profile, large flange, closed end and countersunk are available within the standard range of products. Corrosion Resistance The selection of the material type and coating of the threaded insert should be made on the basis of the corrosion resistance required.

Application

Truck Inner Rails	Wheelable Container	Car Door Switch
Fuel Gauge	Adjustable Foot	Protective Headgear
PCB Connector	Panel Mountings	Extruded Aluminium Profiles

MORE EXAMPLES.....

Installation Tools

• Heavy duty design for demanding production environments
• Can be suspended or hand held
• Quick and simple to operate
• Cycle time less than 3 seconds

Tool	Description
	74200 (Hydro-Pneumatic) Places the full range of threaded inserts
	74201 (Hydro-Pneumatic) Places a range of inserts with metric (up to 8mm) and imperial threads (up to 5/16-24). Check the tool manual for specific styles and sizes
	74401 (Hydro-Pneumatic) Places a range of inserts with metric (up to 10mm) and imperial threads (up to 3/8-24). Check the tool manual for specific styles and sizes
	74405 (Hydro-Pneumatic) Places a range of inserts with metric (up to 10mm) and imperial threads (up to 3/8-24). Check the tool manual for specific styles and sizes