Fasteners that fit just right

DN Staff

September 22, 1997

5 Min Read
Fasteners that fit just right

PROBLEM:Creating a strong right angle in thin sheet-metal applications can be difficult. Cut-outs made in panels to form right angles can reduce EMI/RFI shielding. In addition, bent tabs at the edges or in the middle of sheets, bent flanges, right-angle brackets, and tack welds often reduce design integrity.

SOLUTION: The PEM(R) R'ANGLETM self-clinching fastener provides a strong right-angle attachment point in aluminum sheets as thin as 0.040 inch (1 mm). Pressed into a punched hole in the aluminum sheet, the fastener mounts securely and permanently with the reverse side of the panel remaining flush. Once the fastener is mounted, the second sheet or component can be securely fastened to it with a thread-forming screw. This self-piloting screw "forms" its own thread as it is installed. The result: an extremely tight thread fit that resists vibration and has excellent strip-out characteristics.

R'ANGLE fasteners help maintain panel integrity, reduce EMI/RFI, eliminate welding, and decrease both the amount of loose hardware and the number of assembly steps. In addition, they can be removed and reinstalled repeatedly without compromising the fastener's holding power.

APPLICATIONS:R'ANGLE fasteners are suitable for use in electrical and electronic assemblies.
Penn Engineering & Manufacturing Corp.

Pipe plug reduces leakage

PROBLEM: In standard NPTF pipe plug applications, spiral leakage commonly occurs around the plug helix.

SOLUTION:The MagnasealTM pipe plug with a sealing point feature taps an internal hole to NPTF dimensions and reduces the risk of spiral leakage.

During installation, three annular rings displace material in the tapered and reamed hole 360 degrees around the sealing point. This increases resistance to leakage of gases and fluids. The sealing point also preloads the tapered hole and provides greater resistance to internal pressure than a standard NPTF pipe plug.

The Magnaseal design also eliminates the risk of cross threading during installation, as it forms its own mating threads. In addition, since the Magnaseal forms standard NPTF threads, it can be replaced with an NPTF pipe plug during any necessary field service.

APPLICATIONS: Magnaseal is suited for engine block and transmission applications in the automotive and appliance industries, as well as for pumps and cylinders.
Camcar Textron

Nut and bolt system reduces assembly time

PROBLEM: Installation difficulties, tool change requirements, and torque control, among other concerns, often add to the product assembly process.

SOLUTION: The Industrial EddieBolt nut and bolt system provides the installer with a predetermined preload and a positive mechanical lock upon installation. The bolt features five flutes spaced equally on the threads. The nut is distinguished by three equally spaced "lobes." Installed similarly to a regular nut and bolt system, the nut is free-running to the application. A DeltaRadTM socket, used in conjunction with an impact wrench, drives the nut lobes into the flutes of the bolt. The result is a mechanically locked system that will not vibrate loose.

APPLICATIONS: The EddieBolt system is suited for industrial and aerospace applications.
Fairchild Fasteners

Blind fasteners join delicate materials

PROBLEM: Some fasteners tend to do more damage than good when used in delicate materials, often distorting or deforming soft plastics or thin sheet metals.

SOLUTION: JACK NUT threaded inserts install safely in thin, soft, or brittle materials. When tightened, the body of the JACK NUT collapses to form legs that grip the inside of the mounting surface, leaving a permanent, reusable threaded insert. JACK NUT threaded inserts are not hole-size sensitive and fasten securely despite burrs or uneven substrates. Available in steel or brass, the inserts come with coated flanges: PVC for increased protection against scratching, or Raintite(R), which seals against ambient moisture.

To install, fit the JACK NUT onto the mandrel of the installation tool, then insert it into a predrilled hole until the flange firmly sets against the mounting surface. Fully collapse the insert and remove the installation tool. Pass a machine screw through the part to be fastened and into the JACK NUT, then tighten until snug.

APPLICATIONS: JACK NUT inserts are suited for automotive, electronic, and HVAC assemblies, as well as toys, plastic furniture, and home furnishings.
Emhart Industrial, Div. Europe

Draw latch compensates for bad fits

PROBLEM: In latching applications, panel misalignment and excessive stress or vibration can lead to accidental openings and safety risks.

SOLUTION: Southco's rotary action draw latch operates as a standard draw latch, pulling two panels together with an over-center clamping force--but with important added benefits. A concealed-spring loaded version of the latch compensates up to 1.7 mm (0.07 inch) for mounting hole irregularities, panel variations, and gasket set. It also provides an allowance of 2.3 mm (0.09 inch) deflection when loaded. The latch absorbs shock and vibration and reduces rattling under extreme application conditions. For applications where misalignment is not a concern, a fixed-anchor plate version is available.

Unlike traditional overcenter latches, the rotary action draw latch requires two motions to operate: First lift the wing, then twist counter-clockwise to disengage. This "lift-and-twist" action prevents the latch from snapping open.

APPLICATIONS:The latch can be used in off-highway, RV/caravan, exhibit, and furniture applications. The stainless-steel version is suited for medical and food equipment applications.
Southco, Inc.

Inserts work with thermoplastics

PROBLEM: When an engineer wants to use quarter-turn fasteners in applications involving thermoplastic injection molding, there are few affordable options. Standard threaded fasteners are a common solution, but do not offer quick access or captive hardware.

SOLUTION: Insert receptacles for the "Rapier" quarter-turn fastening system enable affordable mounting in metal housings and thermoplastic moldings. The Rapier system features a cam rolled externally on the body of the fastener. The cam is engaged by tabs on the recessed portion of the receptacle. Two stud diameters and two additional styles of receptacles are available: slip on and clip in.

APPLICATIONS: The fastening system is suited for automotive, aerospace, and defense applications.
DFS International

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