Self Clinching Reduced Flush Head Studs Installation and Performance

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SELF-CLINCHING

Clinch Nuts Flush Nuts Blind Nuts Miniature Nuts Nyloc Nuts Locking Nuts Floating Nuts Flush Head Studs Flush Head Studs for Stainless Steel Reduced Flush Head Studs Thin Panel Non-Flush Studs High Strength Studs Thin Panel High Strength Studs Flush Head Pins Flush Head Tapered Pins Concealed Head Studs Through & Blind Standoffs Grounding Standoffs Thin Panel Standoffs Quick Release Standoffs Keylock Standoffs Concealed Head Standoffs Flush Panel Screw Assembly Panel Fasteners Phillips Head Panel Fasteners Low-Profile Panel Fasteners Plunger Assembly Self-Clinching fastener Do’s and Don’ts Self-Clinching fastener problem solving guides Self-Clinch in harder panels

Testing Method

Torque-out testing of Self-Clinching Reduced Head Studs should be performed by the gradual application of torque as shown while the test panel is securely held in a vice. The bolt must be of a sufficient grade to resist thread stripping. Torque must be gradually applied until failure is observed and a maximum applied torque reading is recorded. Failure mode is the stud turning in the panel, cam-out, or dependent on stud type/size, thread failure.

Performance

Thread size

M2.5

Installation (kN)

Torque-out (Nm)

Pushout (N)

3.0

Pull-thru (N)

280

0.5

1900

5.5

455

1.1

2200

4.2

285

0.7

1300

5.5

485

1.3

2450

M3.5

4.3

280

0.7

1450

6.5

495

1.8

2850

5.4

360

1.1

1600

6.6

570

2.2

3350

11.0

525

2.1

1800

1.2mm Aluminium

Test sheet material

1.2mm Steel

1.2mm Aluminium

1.2mm Steel

1.2mm Aluminium

1.2mm Steel

1.2mm Aluminium

1.2mm Steel

1.2mm Aluminium

1.2mm Steel

19.8

1025

4.5

3800

Max. nut tightening Torque (Nm)

0.41

0.46

0.74

0.58

1.15

0.75

1.70

1.11

2.25

All performance figures are averages obtained over a range of installations and should be used as an indicator only. Panel material, hole preparation, installation tooling and method can affect part performance. We always recommend that you carry out your own tests in the actual application. Please call our sales team and we will be happy to provide you with samples as well as offering technical assistance.

First punch or drill the correct size hole. Do not deburr or chamfer the hole prior to installation as this will remove material required during the clinching process. It is preferable to install the fastener from the punch side of the panel. Place the fastener in the prepared hole in the panel and then locate the fastener in the anvil, ensuring that you are using the appropriate anvil type for the panel thickness like in the diagram above. With the panel held level, apply a parallel squeezing force until the head is installed flush to the panel surface. Do not over squeeze the fastener into the panel as this will result in panel deformation. When installing Self-Clinching fasteners, please pay attention to the minimum hole centreline to edge and parent material hardness limitations.

Anvil Dimensions

B +0.1

3.6

3.1

4.1

4.6

A +0.08

3.03

2.53

3.53

4.03

Thread size

M2.5

M3.5

5.6

5.03

Countersunk hole style anvil for 1.50mm or less panel thickness.

Straight thru hole style anvil for 1.51mm minimum panel thickness.

Do not remove any extra material or chamfer the hole as this could result in improper installation or reduced performance.

HRB (ROCKWELL HARDNESS B SCALE) Ensure that you are installing into a panel that is ductile and at or below the published maximum recommended hardness for the fastener.

Ensure that attention is paid to the minimum hole centreline to edge dimension for each fastener. Installing too close to an edge or bend could result in improper installation or reduced performance. Minimum centreline to edge dimensions shown for each fastener apply to one edge only. If this distance is applied on multiple sides there will be significant panel distortion unless the panel edges are supported during installation.

Material & Finish

Electro Zinc Plated Carbon Steel (ZI) parts are suitable for installation in ductile panels with a maximum recommended hardness of 80 HRB. 300 Series Stainless Steel (A2) parts are suitable for installation in ductile panels with a maximum recommended hardness of 70 HRB.

Part Number Examples

Part number is made up as follows: (Type)-(Thread)-(Length)-(Material/Finish code) For example: NFHL-M3-10-ZI (Reduced Head Stud-M3-10mm long-electro zinc plated carbon steel) NFHL-M4-12-A2 (Reduced Head Stud-M4-12mm long-stainless steel) Use part designation NFHLD to specify a dog-point thread lead-in (special order).

Info

Self-Clinching Reduced Head Studs provide strong low displacement captivated male threads in thin panels and are suitable for installation closer to the edge of the panel than normal Flush Head Studs. Utilising a special proven castellated clinch feature, this fastener has good torque-out, pull-through and push-out characteristics whilst providing a flush finish on the underside of the panel, meaning that minimal surface finishing is required after installation. Like all self clinching fasteners they are installed using a parallel squeezing action, so require access to both sides of the panel. Reduced Head Studs are available in a range of thread sizes and lengths, manufactured from electro zinc plated steel, 300 series stainless steel and are suitable for installation in ductile steel and aluminium panels with a recommended maximum hardness of 80 HRB for steel parts and 70 HRB for 300 series stainless steel parts. Reduced Head Studs can also be supplied with a dog-point thread lead-in to aid component assembly.

Dimensional Data Self-Clinching fastener Do’s & Don’ts Self-Clinching fastener problem solving guides Downloadable Data Sheet Back

Installation

Type NFHL

SELF-CLINCHING REDUCED HEAD STUDS

Push-out testing of Self-Clinching Reduced Head Studs should be performed by the gradual application of a load as shown above. Bushing height should be sufficient to allow free downward movement of the stud during testing. The bushing bore must be centred on the head of the stud.

Hardened bush. A minimum of 6 fully engaged threads is recommended on both sides.

Test panel held firmly in vice.

Applied torque from dial measuring torque wrench.

Minimum grade 5 bolt (grade 8 for NHTS & NHFE fasteners).

Pull-through test for Self-Clinching Reduced Head Studs should be performed by the gradual application of an axial load as shown. A hardened bushing with a through-hole 0.5mm greater than the diameter of the thread should be centred over the stud and inserted into the test rig lower link. A hardened threaded bushing should be inserted into the test rig upper link and screwed down onto the stud. An axial load is then gradually applied on a tensile testing machine to separate the links until a failure point is reached. Please note that the pull-through values obtained during this test do not indicate the axial strength of the stud threads. Pull-through values pertain only to the amount of force required to pull the stud through the panel.

Tensile testing rig upper link

Tensile testing rig lower link

Hardened bushing

Hardened threaded bushing. A minimum of 6 fully engaged threads is recommended.

Applied Load.

Thread dia. + 0.5mm

Hardened bushing with sufficient wall thickness to withstand applied compression load.

Head Dia. + 1.6mm

Test panel.

Compression rig base.

Torque-through testing of Self-Clinching Reduced Head Studs should be performed by the gradual application of torque as shown while the test panel is securely held in a vice. The hex nut must be of sufficient grade to resist thread stripping. Torque must be gradually applied until failure is observed. Failure mode may vary depending on fastener type, size, length and the properties of the panel the part is installed into. The fastener may actually fracture instead of the head pulling through the panel. Please note that the torque-through values obtained during this test do not indicate the axial strength of the stud threads, the allowable nut tightening torque or the design loading of the assembled component. Torque-through values pertain only to the amount of torque required to pull the stud through the panel.