Top 12 Flange Nuts

A flange nut is a nut with a wide rim, which acts as an attached washer. It distributes the pressure exerted by the nut over a larger area, reducing the likelihood of damage to the item the nut is applied to. This also prevents the nut from coming loose over time.

Browse Best Flange Nuts

1/2-13 Serrated Flange Hex Lock Nuts, Stainless Steel 18-8 (304), Bright Finish, ...

  • Brand Name: MewuDecor
  • Size Options: 1/2-13 (10 PCS), 1/2-13 (20 PCS), 1/4-20 (25 PCS), 1/4-20 (50 Pack), 1/4-20 (100 PCS) and 15 other options.
  • Material Options: Stainless Steel
  • Item Weight: 7.8 ounces
  • Satisfaction Score: 101%
  • Dimensions: 2.91 x 2.28 x 1.81 inches
  • Overall Score: 9.7
Store Website: www.amazon.com

FullerKreg (Pack of 25) M4 x 0.7 A2 Stainless Steel DIN 6926 Hex Flange Nylon ...

  • Brand Name: Fullerdongluo
  • Model Name: 43398-23359
  • Size Options: M4 25PCS, M5 25PCS, M8 10PCS, M10 5PCS
  • Color Options: Plain
  • Material Options: Stainless Steel
  • Item Weight: 0.634 ounces
  • Satisfaction Score: 97%
  • Dimensions: 3.39 x 2.36 x 0.87 inches
  • Overall Score: 9.5
Store Website: www.amazon.com

M6 Thread 304 Stainless Steel Serrated Flange Metric Hex Lock Nuts 26PCS

  • Brand Name: SpeedDa
  • Model Name: 43237-2
  • Size Options: 6 x 2 x 0.5 inches
  • Color Options: Silver Tone
  • Material Options: Stainless Steel
  • Item Weight: 4.6 ounces
  • Satisfaction Score: 99%
  • Overall Score: 9.3
Store Website: www.amazon.com

1/2-13 Serrated Flange Hex Lock Nuts, Bright Finish,304 Stainless Steel 18-8, ...

  • Brand Name: EASTLO
  • Model Name: AN100504-10
  • Size Options: 1/2-13 (10 pcs), 1/2-13 (20 pcs), 1/4-20 (30pcs), 1/4-20 (50 pcs), 1/4-20 (100 pcs) and 14 other options.
  • Color Options: Silver
  • Material Options: Stainless Steel
  • Item Weight: 8 ounces
  • Satisfaction Score: 98%
  • Dimensions: 4 x 4 x 0.7 inches
  • Overall Score: 9.7
Store Website: www.amazon.com

SNUG Fasteners (SNG269) Fifty (50) 1/4-20 Zinc Plated Serrated Flange Hex Lock ...

  • Brand Name: SNUG Fasteners
  • Model Name: SNG269
  • Material Options: Zinc plated
  • Item Weight: 6.7 ounces
  • Satisfaction Score: 98%
  • Dimensions: 4 x 6 x 0.5 inches
  • Overall Score: 9.1
Store Website: www.amazon.com

FullerKreg M4 x 0.7mm 304 Stainless Steel Serrated Hex Flange Lock Nuts (100 ...

  • Brand Name: Fullerkreg
  • Model Name: 43398-23298
  • Size Options: M4 100PCS, M8 25PCS, M10 10PCS, M12 5PCS
  • Material Options: Stainless Steel
  • Item Weight: 4.8 ounces
  • Satisfaction Score: 94%
  • Dimensions: 3.3 x 2.3 x 0.9 inches
  • Overall Score: 9.1
Store Website: www.amazon.com

H2o Kayaks H2o M5 Neoprene Well Nut Inc Stainless Steel Pozi Screw Long Type ...

  • Brand Name: H2o Kayaks
  • Model Name: D
  • Size Options: M5, m5
  • Material Options: MARINE GRADE STEEL & RUBBER
  • Satisfaction Score: 96%
  • Dimensions: 4.49 x 2.91 x 0.55 inches; 1.59 Ounces
  • Overall Score: 9.1
Store Website: www.amazon.com

4Pcs 3mm Flange Coupling Connector, Rigid Guide Model Coupler Accessory, Shaft ...

  • Brand Name: Daier
  • Model Name: H415*4
  • Size Options: 3mm, 3.17mm, 4mm, 5mm, 6mm and 2 other options.
  • Material Options: Metal
  • Item Weight: 1.58 ounces
  • Satisfaction Score: 100%
  • Dimensions: 4.8 x 2.2 x 0.2 inches
  • Overall Score: 9.7
Store Website: www.amazon.com

(20) 3/8-16 Hex Flange Nuts Grade 8 Phos & Oil

  • Brand Name: BoltsandNuts.com
  • Model Name: 37CNHF8P/FS-217
  • Size Options: 3/8"-16
  • Satisfaction Score: 100%
  • Overall Score: 8.9
Store Website: www.amazon.com

SNUG Fasteners (SNG271) Forty (40) 3/8-16 Zinc Plated Serrated Flange Hex Lock ...

  • Brand Name: SNUG Fasteners
  • Model Name: SNG271
  • Material Options: Zinc plated
  • Item Weight: 10.9 ounces
  • Satisfaction Score: 98%
  • Dimensions: 4 x 6 x 0.5 inches
  • Overall Score: 9.7
Store Website: www.amazon.com

Hilitchi 140-Pcs M3 M4 M5 M6 M8 M10 M12 Hex Flange Nuts Assortment Kit - 304 ...

  • Brand Name: Hilitchi
  • Model Name: HFN140
  • Size Options: M4, m5
  • Material Options: Stainless Steel
  • Satisfaction Score: 94%
  • Dimensions: 6.8 x 3.9 x 0.9 inches; 1.2 Pounds
  • Overall Score: 8.7
Store Website: www.amazon.com

Prime-Line 9094921 Flange Nuts, Class 8 Metric, M8-1.25, Zinc Plated Steel, ...

  • Brand Name: Prime-Line
  • Model Name: 9094921
  • Size Options: M8-1.25
  • Color Options: Zinc Plated Steel
  • Material Options: Steel
  • Item Weight: 2.43 ounces
  • Satisfaction Score: 100%
  • Dimensions: 1.5 x 3 x 4 inches
  • Overall Score: 9.9
Store Website: www.amazon.com

Flange Nuts Buying Guide

In bolts and fasteners, flange nuts are specialized hex nuts with a wide circular flange on the bottom. They come in two main variants: flange lock nuts, which use prevailing torque to fasten, and serrated flange nuts, which grip the applied part using serrations on the bearing surface. They are suitable for use with oversized and irregular holes as the flange covers the gap. These nuts are used in garden equipment, automotive assembly, metal joinery, and other marine and industrial applications. Here is a guide for selecting the right kind of flange nut for a project.

Application and area

These two kinds of nuts use different mechanisms to fasten, and the areas that they can be applied to are limited by them. For starters, flange lock nuts use a deformed thread to create prevailing torque (a resistance to tightening) as they are fastened. So they can't be used to secure thick materials, as the nut needs to be fully engaged for the locking mechanism to work, and they are best not used with a long assembly, as forcing the nut over a long distance can damage the locking mechanism. For similar reasons, they can't be reused too much.

Serrated flange nuts, on the other hand, can be reused. These work by creating small distortions on the surface of the material the nut is applied to, creating a ratchet locking mechanism. Thus, it can't be used in situations where there is a protective coating on said material, as the distortions can make it vulnerable to corrosion around the joint. It also cannot be used with washers because the flange has to make contact with the surface.

Finishing and protection

Flange lock nuts are most commonly available in Grade 8 steel. They must be of the same hardness as the bolt, or the pressure exerted during installation may damage either or both of them. These lock nuts may have a finish of black phosphate and oil or yellow plated zinc. Both provide some degree of corrosion resistance, though the phosphate and oil offer added lubricity and the zinc better protection from rusting. Some flange lock nuts have a Nylon insert that sits tight against the fastener to prevent loosening.

Serrated flange nuts are available in zinc plated steel, which provides some protection, but if corrosion is a concern, stainless steel nuts are the best option by far.