ND Expandable Mastics


ND Industries’ heat expandable mastic products are used in a wide variety of applications providing economical solutions for the prevention of metal-to-metal contact, vibration, and noise-related problems (sometimes referred to as flutter). An excellent anti-flutter compound, ND Expandable Mastics are an extruded product made in standard, custom, or complex die cut shapes and thicknesses to meet customer requirements for sealing, noise dampening, and vibration reduction.

How it Works

ND Expandable Mastic extrusions are ready-to-use in an uncured form and can be applied or bonded to any metal surface prior to the application of heat. When heat is applied, generally in a primer oven, a reaction takes place that causes the material to expand and adhere to the metal surfaces and create a seal while filling all space between the metals. Our product offers expansion rates ranging from 100% to 700%. The material is stable, non-volatile, resistant to most chemicals, has a long shelf-life, and is compatible with production phosphatizing and paint systems.


Suppress flutter & vibration

When used as backing for sheet metal panels, it prevents flutter, seals, reduces vibration, and deadens sound.


ND Expandable Mastics will provide some metal-to-metal bonding once it is fully cured.

Volume filler

ND Expandable Mastics swell to fill the cavity it is placed in. Between two layers of sheet metal, the material acts as an insulator from moisture, air, dust, and noise.


In a cured or uncured state, ND Expandable Mastics secure the intended area from penetration by moisture, gases, dust, sound, and vibration.


ND Expandable Mastics offer excellent adhesion to metal substrates - without additional adhesives or tape.

Standard Profiles

ND Expandable Mastics are available in a variety of lengths and diameters to provide a quick and flexible response to a customer's need.


  • Saves Time: ND Expandable Mastics are easy to incorporate into high-volume production functions and can be applied with minimal time, effort, or training, or can be assembled for you by ND.
  • Saves Money: ND Expandable Mastics are inexpensive and yet provide excellent high-quality expansion and sealing.
  • Easy to Use: ND Expandable Mastics require minimal employee training for efficient use.
  • Meets Automotive Specs: ND Expandable Mastics meet specifications for the “Big Three” automakers.


  • ND Expandable Mastics are stable, with a long shelf life.
  • ND can specially formulate Expandable Mastics to meet customer specifications (e.g. – penetrometers, expansion, etc.). ND will work with you to produce extremely high expansion rates – higher than any other Expandable mastic supplier.
  • For unique applications, ND Industries can provide the material in custom die cut shapes.
  • ND Expandable Mastics are non-staining, non-volatile, and require little cleanup in production operations.

ND Expandable Mastics Competes With



Automotive Floor Boards, Firewall, Sound Deadening, Interior applications, Automotive Gaskets, Automotive Washers, drain plugs

Technical Data

ProductDescriptionColorCompetes WithSpecific GravityExpansionHardness Shore ANeedle PenetrometerWater AbsorptionSolids ContentForm Product is SoldSpec. Meets or Exceeds
ND EM223Soft, heat-expandable washers for sealing against moisture, air, dust, and the prevention of bolt torque loss.TanL&L Products: L10411.45100 - 200%303.8 mm2.20%99%WashersMS-CD64, GM3640M, MS-CD466A,
ND 400Injection molded or die-cut parts that do not require expansion. Similar formula to ND 500 without expansion.Black1.32300 - 400%503.8 mm3.00%97%Die-Cut Parts,
4'' Wide Strips,
3' Long
WSS-M18P11-B, WSS-M4G183-D
ND 500Injection molded or die-cut parts designed to, but not limited to, seal automotive e-coat drain holes against dust, air, and moisture intrusion.Blue1.31150 - 250%852.1 mm1.50%99%Pellets,
Die-Cut Parts,
9¾" Wide Roll
MS-CD466E, MS-CD451,
ND 700Injection molded or die-cut parts designed to seal automotive interior and exterior body joints against gasoline, moisture, air, and dust.Black1.25300 - 450%900.9 mm2.20%98%Pellets,
Die-Cut Parts,
9¾" Wide Roll
ND 750Injection molded or die-cut parts that require higher expansion than ND 700.Black1.25500 - 700%900.9 mm2.50%98%Pellets,
Die-Cut Parts,
9¾" Wide Roll


Particular formulations of ND Expandable Mastics meet or exceed the performance requirements of the following specifications and/or standards:

Spec ForSpec NumberND ProcessND Material
Fiat ChryslerMS-CD451 TYPE EExpandable MasticsND 700
Fiat ChryslerMS-CD466 TYPE EExpandable MasticsND 500
Fiat ChryslerMS-CD64Expandable MasticsND EM223
FordESB-M18P11-AExpandable MasticsND 400
FordESB-M4G223-AExpandable MasticsND EM223
FordWSS-M21P27-A1Expandable MasticsND 500
FordWSS-M21P27-A2Expandable MasticsND 500
FordWSS-M21P27-A3Expandable MasticsND 500
FordWSS-M21P27-A4Expandable MasticsND 500
FordWSS-M21P27-A5Expandable MasticsND 500
General Motors9984188Expandable MasticsND 400
General Motors9984192Expandable MasticsND EM223
General MotorsGM3640MExpandable MasticsND EM223

Safety, Technical & Product Data Sheets

Process NameMaterialSafety Data Sheet (Applied)Technical Data Sheet (Applied)Process Data Sheet
ND Expandable MasticsND 400ND2051ND400 - TDS (Applied)Expandable Mastics - PDS
ND Expandable MasticsND 500Expandable Mastics - PDS
ND Expandable MasticsND 510ND3450ND510 - TDS (Applied)Expandable Mastics - PDS
ND Expandable MasticsND 700ND3075ND700 - TDS (Applied)Expandable Mastics - PDS
ND Expandable MasticsND 750ND3179ND750 - TDS (Applied)Expandable Mastics - PDS
ND Expandable MasticsND EM223ND3068EM223 - TDS (Applied)Expandable Mastics - PDS
Increase product quality while saving time and money with Pre-Applied adhesives and sealants.