Inserts - Expansion - Press In - 303 Stainless Steel

Inserts -> Expansion -> Press In -> 303 Stainless Steel

There are 8 products in the sub-categories of Inserts - Expansion - Press In - 303 Stainless Steel. Browse the Inserts - Expansion - Press In - 303 Stainless Steel products table.

Category Details

A selection of 303 Stainless Steel Press In Expansion Inserts. Use for cored or drilled holes in plastics. Designed to replace molded in inserts and threads in plastic casings. Also known as threaded inserts.

  • Used to create a reusable threaded hole in a material by expanding once it is in place.
  • Installed by being pressed into a pre-drilled hole, and a subsequent tightening of a screw or bolt causes it to expand and grip the material's interior, providing a strong, stable connection.
  • Common types are for wood, plastic, and masonry, with different designs tailored to the material's properties.
  • Material : 303 Stainless Steel
  • Easiest inserts to install - simply push into a pre-moulded hole.
  • Used with plastics or other materials. Material must be strong enough to withstand the expansion of the insert.
  • The insertion of the screw locks the external knurls into the wall of the hole.
  • Provides excellent thread durability but where maximum strength is required other inserts shown in this catalogue should be preferred.

Miniature Bearings Australia - MBA Minibearings

Additional resources:


A more concise listing may be found in the Inserts - Expansion - Press In - 303 Stainless Steel category on the Small Parts & Bearings online store.
Internal Thread Rec. Hole Diameter Length (L) Recommended Hole Diameter (A) Knurled OD (B) Indicative
Image
Expansion Inserts - 2-56 UNC - 2.18mm - 3.17x3.96 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
2-56 UNC (2.18mm)
Rec. Hole Diameter
3.17
mm
+ 0.000 / - 0.254
(Equiv. 0.125 in.)
Length (L)
3.96
mm
+/- 0.25
(Equiv. 0.156 in.)
Knurled OD (B)
3.18
mm
Expansion Inserts - 2-56 UNC - 2.18mm - 3.17x3.96 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-022C-039-S3 (Each)
20 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.86 AUD
$5.84 AUD $4.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 20 available can be backordered.
Internal Thread Rec. Hole Diameter Length (L) Recommended Hole Diameter (A) Indicative
Image
Expansion Inserts - 2-56 UNC - 2.18mm - 3.17x3.96 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
2-56 UNC (2.18mm)
Rec. Hole Diameter
3.17
mm
+ 0.000 / - 0.254
(Equiv. 0.125 in.)
Length (L)
3.96
mm
+/- 0.25
(Equiv. 0.156 in.)
Expansion Inserts - 2-56 UNC - 2.18mm - 3.17x3.96 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 3.18 mm   
Part Number: IN-EP-022C-039-S3 (Each)
20 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.86 AUD
$5.84 AUD $4.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

20 Available Now. Backorder if more than 20.
Expansion Inserts - 4-40 UNC - 2.85mm - 3.96x4.78 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
4-40 UNC (2.85mm)
Rec. Hole Diameter
3.96
mm
+ 0.000 / - 0.254
(Equiv. 0.156 in.)
Length (L)
4.78
mm
+/- 0.25
(Equiv. 0.188 in.)
Knurled OD (B)
3.97
mm
Expansion Inserts - 4-40 UNC - 2.85mm - 3.96x4.78 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-029C-048-S3 (Each)
20 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.95 AUD
$4.95 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 20 available can be backordered.
Expansion Inserts - 4-40 UNC - 2.85mm - 3.96x4.78 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
4-40 UNC (2.85mm)
Rec. Hole Diameter
3.96
mm
+ 0.000 / - 0.254
(Equiv. 0.156 in.)
Length (L)
4.78
mm
+/- 0.25
(Equiv. 0.188 in.)
Expansion Inserts - 4-40 UNC - 2.85mm - 3.96x4.78 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 3.97 mm   
Part Number: IN-EP-029C-048-S3 (Each)
20 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.95 AUD
$4.95 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

20 Available Now. Backorder if more than 20.
Expansion Inserts - 6-32 UNC - 3.5mm - 4.75x6.35 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
6-32 UNC (3.5mm)
Rec. Hole Diameter
4.75
mm
+ 0.000 / - 0.254
(Equiv. 0.187 in.)
Length (L)
6.35
mm
+/- 0.25
(Equiv. 0.25 in.)
Knurled OD (B)
4.77
mm
Expansion Inserts - 6-32 UNC - 3.5mm - 4.75x6.35 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-035C-064-S3 (Each)
30 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$3.59 AUD
$3.59 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 30 available can be backordered.
Expansion Inserts - 6-32 UNC - 3.5mm - 4.75x6.35 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
6-32 UNC (3.5mm)
Rec. Hole Diameter
4.75
mm
+ 0.000 / - 0.254
(Equiv. 0.187 in.)
Length (L)
6.35
mm
+/- 0.25
(Equiv. 0.25 in.)
Expansion Inserts - 6-32 UNC - 3.5mm - 4.75x6.35 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 4.77 mm   
Part Number: IN-EP-035C-064-S3 (Each)
30 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$3.59 AUD
$3.59 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

30 Available Now. Backorder if more than 30.
Expansion Inserts - 8-32 UNC - 4.17mm - 5.53x7.95 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
8-32 UNC (4.17mm)
Rec. Hole Diameter
5.53
mm
+ 0.000 / - 0.254
(Equiv. 0.218 in.)
Length (L)
7.95
mm
+/- 0.25
(Equiv. 0.313 in.)
Knurled OD (B)
5.54
mm
Expansion Inserts - 8-32 UNC - 4.17mm - 5.53x7.95 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-042C-079-S3 (Each)
10 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$9.86 AUD
$9.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 10 available can be backordered.
Expansion Inserts - 8-32 UNC - 4.17mm - 5.53x7.95 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
8-32 UNC (4.17mm)
Rec. Hole Diameter
5.53
mm
+ 0.000 / - 0.254
(Equiv. 0.218 in.)
Length (L)
7.95
mm
+/- 0.25
(Equiv. 0.313 in.)
Expansion Inserts - 8-32 UNC - 4.17mm - 5.53x7.95 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 5.54 mm   
Part Number: IN-EP-042C-079-S3 (Each)
10 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$9.86 AUD
$9.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

10 Available Now. Backorder if more than 10.
Expansion Inserts - 10-32 UNF - 4.76mm - 6.34x9.53 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
10-32 UNF (4.76mm)
Rec. Hole Diameter
6.34
mm
+ 0.000 / - 0.254
(Equiv. 0.25 in.)
Length (L)
9.53
mm
+/- 0.25
(Equiv. 0.375 in.)
Knurled OD (B)
6.35
mm
Expansion Inserts - 10-32 UNF - 4.76mm - 6.34x9.53 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-048F-095-S3 (Each)
10 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.68 AUD
$5.62 AUD $4.68 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 10 available can be backordered.
Expansion Inserts - 10-32 UNF - 4.76mm - 6.34x9.53 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
10-32 UNF (4.76mm)
Rec. Hole Diameter
6.34
mm
+ 0.000 / - 0.254
(Equiv. 0.25 in.)
Length (L)
9.53
mm
+/- 0.25
(Equiv. 0.375 in.)
Expansion Inserts - 10-32 UNF - 4.76mm - 6.34x9.53 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 6.35 mm   
Part Number: IN-EP-048F-095-S3 (Each)
10 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$4.68 AUD
$5.62 AUD $4.68 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

10 Available Now. Backorder if more than 10.
Expansion Inserts - 1/4-20 UNC - 6.35mm - 7.93x12.7 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
1/4-20 UNC (6.35mm)
Rec. Hole Diameter
7.93
mm
+ 0.000 / - 0.254
(Equiv. 0.312 in.)
Length (L)
12.70
mm
+/- 0.25
(Equiv. 0.5 in.)
Knurled OD (B)
7.94
mm
Expansion Inserts - 1/4-20 UNC - 6.35mm - 7.93x12.7 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-064C-127-S3 (Each)
6 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$7.14 AUD
$8.56 AUD $7.14 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 6 available can be backordered.
Expansion Inserts - 1/4-20 UNC - 6.35mm - 7.93x12.7 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
1/4-20 UNC (6.35mm)
Rec. Hole Diameter
7.93
mm
+ 0.000 / - 0.254
(Equiv. 0.312 in.)
Length (L)
12.70
mm
+/- 0.25
(Equiv. 0.5 in.)
Expansion Inserts - 1/4-20 UNC - 6.35mm - 7.93x12.7 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 7.94 mm   
Part Number: IN-EP-064C-127-S3 (Each)
6 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$7.14 AUD
$8.56 AUD $7.14 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

6 Available Now. Backorder if more than 6.
Expansion Inserts - 5/16-18 UNC - 7.94mm - 9.52x14.3 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
5/16-18 UNC (7.94mm)
Rec. Hole Diameter
9.52
mm
+ 0.000 / - 0.254
(Equiv. 0.375 in.)
Length (L)
14.30
mm
+/- 0.25
(Equiv. 0.563 in.)
Knurled OD (B)
9.53
mm
Expansion Inserts - 5/16-18 UNC - 7.94mm - 9.52x14.3 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-079C-143-S3 (Each)
6 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$7.05 AUD
$8.45 AUD $7.05 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Larger quantities than the 6 available can be backordered.
Expansion Inserts - 5/16-18 UNC - 7.94mm - 9.52x14.3 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
5/16-18 UNC (7.94mm)
Rec. Hole Diameter
9.52
mm
+ 0.000 / - 0.254
(Equiv. 0.375 in.)
Length (L)
14.30
mm
+/- 0.25
(Equiv. 0.563 in.)
Expansion Inserts - 5/16-18 UNC - 7.94mm - 9.52x14.3 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 9.53 mm   
Part Number: IN-EP-079C-143-S3 (Each)
6 Available Now | Further orders can be expected around Thu, Aug 06, 2026
$7.05 AUD
$8.45 AUD $7.05 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

6 Available Now. Backorder if more than 6.
Expansion Inserts - 3/8-16 UNC - 9.53mm - 11.1x15.88 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
3/8-16 UNC (9.53mm)
Rec. Hole Diameter
11.1
mm
+ 0.000 / - 0.254
(Equiv. 0.437 in.)
Length (L)
15.88
mm
+/- 0.25
(Equiv. 0.625 in.)
Knurled OD (B)
11.11
mm
Expansion Inserts - 3/8-16 UNC - 9.53mm - 11.1x15.88 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80   
Part Number: IN-EP-095C-159-S3 (Each)
Out of Stock | Backorder Now | Backorder now for delivery around Thu, Aug 06, 2026
$11.86 AUD
$14.24 AUD $11.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Backorder: Out of Stock.
Expansion Inserts - 3/8-16 UNC - 9.53mm - 11.1x15.88 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Internal Thread
3/8-16 UNC (9.53mm)
Rec. Hole Diameter
11.1
mm
+ 0.000 / - 0.254
(Equiv. 0.437 in.)
Length (L)
15.88
mm
+/- 0.25
(Equiv. 0.625 in.)
Expansion Inserts - 3/8-16 UNC - 9.53mm - 11.1x15.88 mm Press In - Stainless Steel 303/304 Similar to A2, 18-8 HRB80 Insert
Material: Stainless Steel 303/304 (Similar to A2, 18-8) HRB80    Knurled OD (B): 11.11 mm   
Part Number: IN-EP-095C-159-S3 (Each)
Out of Stock | Backorder Now | Backorder now for delivery around Thu, Aug 06, 2026
$11.86 AUD
$14.24 AUD $11.86 AUD
Each
Excludes GST and overseas Taxes & Duties
Quantity Required

Backorder: Out of Stock.