Ultrasonic/Heat Staking Inserts

SI (Standard Inserts) Ultrasonic/Heat Staking Inserts are hexagonal-shaped body inserts that provide rotational torque resistance and knurling provides torque out resistance. The heat staking inserts are installed by pressing the insert into the mounting hole with a thermal press to melt the plastic surrounding the insert. The SI® brand inserts employ press-in and heat/ultrasonic installation methods to provide strong, reusable, and permanent threads in plastic. These SI® inserts are available in brass, stainless steel, and aluminum. The applications include wearables, smartphones, handheld devices, automotive, aerospace and defense, medical, transportation, industrial, and recreational equipment.

Results: 268
Select Image Part # Mfr. Description Datasheet Availability Pricing (USD) Filter the results in the table by unit price based on your quantity. Qty. RoHS ECAD Model Product Type Material Mounting Hole Size Length Outside Diameter Thread Size Packaging
SI Mounting Hardware ULTRASONIC INSERT, BRASS 187,778In Stock
12,674On Order
$0.26
$0.178
$0.143
$0.134
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 3.58 mm 5.56 mm 4.37 mm M3
SI Mounting Hardware HI-TORQUE INSERT, BRASS 13,090In Stock
$0.37
$0.26
$0.208
$0.196
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 0.223 in 0.321 in 0.243 in 8-32
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 5,335In Stock
10,000Expected 11/2/2026
$1.06
$0.793
$0.617
$0.582
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 5.67 mm 8.15 mm 6.17 mm M4
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 3,764In Stock
$1.21
$0.898
$0.707
$0.60
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 0.316 in 0.5 in 0.342 in 1/4-20
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS STEEL 3.43X3.86 M3 THREAD ULTRASONIC HEAT STAKING DIAGONAL 8,586In Stock
$0.81
$0.575
$0.461
$0.434
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 4.01 mm 3.43 mm 4.55 mm M3
SI Mounting Hardware ULTRASONIC INSERT, STAINLESS 6,833In Stock
$0.66
$0.464
$0.372
$0.335
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 0.185 in 0.25 in 0.219 in 6-32
SI Mounting Hardware HI-TORQUE INSERT, BRASS 60,228In Stock
$0.37
$0.263
$0.21
$0.189
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 4.01 mm 5.74 mm 4.55 mm M3
SI Mounting Hardware HI-TORQUE INSERT, BRASS 3.43X3.86 M3 THREAD ULTRASONIC HEAT STAKING DIAGONAL 14,694In Stock
$0.41
$0.291
$0.233
$0.209
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 4.01 mm 3.43 mm M3
SI Mounting Hardware ULTRASONIC,INSERT,STAINLESS 9,496In Stock
$1.00
$0.743
$0.579
$0.545
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 7.06 mm 11.1 mm 8.33 mm M5
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS STEEL 3.18X3.07 M2 THREAD ULTRASONIC HEAT STAKING DIAGONAL 9,951In Stock
$0.54
$0.381
$0.305
$0.274
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 3.23 mm 3.18 mm 3.73 mm M2
SI Mounting Hardware ULTRASONIC INSERT, BRASS 9,560In Stock
$0.64
$0.453
$0.363
$0.327
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 6.25 mm 9.53 mm 7.54 mm M5
SI Mounting Hardware ULTRASONIC INSERT, STAINLESS 10,254In Stock
$0.70
$0.492
$0.394
$0.355
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 3.89 mm 3.43 mm 4.37 mm M2.5
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 9,083In Stock
$1.32
$0.978
$0.762
$0.718
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 8.03 mm 12.7 mm 8.69 mm M6
SI Mounting Hardware HI-TORQUE INSERT, BRASS 9,769In Stock
$0.94
$0.662
$0.53
$0.478
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 6.43 mm 9.53 mm 7.92 mm M5
SI Mounting Hardware HI-TORQUE INSERT, BRASS 3.18X3.07 M2 THREAD ULTRASONIC HEAT STAKING DIAGONAL 9,585In Stock
$0.47
$0.333
$0.267
$0.24
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 3.23 mm 3.18 mm M2
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 10,328In Stock
$0.86
$0.61
$0.489
$0.44
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 4.01 mm 5.74 mm 4.55 mm M2.5
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 36,897In Stock
$0.85
$0.606
$0.485
$0.437
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 4.01 mm 5.74 mm 4.55 mm M3
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS STEEL 4.70X5.51 M4 THREAD ULTRASONIC HEAT STAKING DIAGONAL 3,711In Stock
10,000Expected 11/17/2026
$1.10
$0.827
$0.644
$0.607
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 5.67 mm 4.7 mm 6.17 mm M4
SI Mounting Hardware HI-TORQUE INSERT, STAINLESS 6,901In Stock
$0.93
$0.695
$0.541
$0.51
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 6.43 mm 9.52 mm 6.93 mm M5


SI Mounting Hardware ULTRASONIC INSERT, BRASS 23,744In Stock
25,000Expected 2/12/2027
$0.22
$0.159
$0.127
$0.115
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 3.89 mm 3.43 mm 4.37 mm M3
SI Mounting Hardware HI-TORQUE INSERT, BRASS 14,912In Stock
$0.46
$0.332
$0.266
$0.239
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 3.23 mm 4 mm 3.73 mm M2
SI Mounting Hardware HI-TORQUE INSERT, BRASS 4.70X5.51 M4 THREAD ULTRASONIC HEAT STAKING DIAGONAL 6,246In Stock
$0.49
$0.342
$0.274
$0.258
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 5.67 mm 4.7 mm M4
SI Mounting Hardware HI-TORQUE INSERT, BRASS 27,191In Stock
11,000Expected 11/10/2026
$0.60
$0.429
$0.343
$0.309
Min.: 1
Mult.: 1
Inserts Threaded Insert Brass 5.67 mm 8.15 mm 7.14 mm M4
SI Mounting Hardware ULTRASONIC INSERT, STAINLESS 9,642In Stock
$0.48
$0.343
$0.275
$0.247
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 3.89 mm 3.43 mm 4.37 mm M3
SI Mounting Hardware ULTRASONIC INSERT, STAINLESS 40,472In Stock
68,141On Order
$0.52
$0.371
$0.297
$0.267
Min.: 1
Mult.: 1
Inserts Threaded Insert Stainless Steel 3.58 mm 5.56 mm 4.37 mm M3