The Dura Bath Additive Is The Difference

Some of these parts were plated in a conventional hard chrome bath and others were plated in a bath using one of the Dura Additives. They may look the same with regards to surface appearance, but there is a huge difference in the quality and structure of the hard chrome deposit.

The ones plated with the Dura additive will far outlast the other ones in service because they have greatly improved metallurgical properties.

These have the benefit of greater hardness, a finer deposit structure, better adhesion, improved fatigue limit, reduced surface friction, less internal stress and better corrosion resistance. This provides a much longer service life on your parts.
To improve your chrome deposit is to improve your business.

Why This Is Important
The life of a single component or an entire assembly depends upon the properties of the hard chrome deposit. Premature failures within this relatively thin layer of chromium can have catastrophic results causing expensive down time and repairs. Manufacturers want the best hard chrome deposit available on their parts. Job shops want to provide their customers with the best quality possible. Both will specify that a Dura Additive is used for their plating because using a Dura bath additive improves the deposit properties.
The Dura additives also provides significant cost savings as they are used with generic chromic acid and there are no expensive proprietary blends to buy.

Dura is the “Next Technology” in hard chrome plating.

Improved Deposit
Some of the benefits of using a Dura additive in your hard chrome baths include:

Property	Standard Bath	Dura -3000
Technology:	Old	New
Crack Type:	macro	ultra micro
Crack Density (per lineal inch):	50, typical	3,000
Hardness (RC):	56-60	72-74
Friction (static):	0.16	0.12
Wear Resistance (Taber grams):	2.3	1.5
Surface Finish (micro-nodules):	Rougher	Very Smooth
Oil Retention :	Fair	Excellent
Adhesion (psi):	90,000	130,000
Fatigue Limit (psi):	45,000	90,000
Internal Stress:	tensile	compressive
Corrosion Resistance (5% Salt Spray):	2-8 hours	25-35 hours
Brightness:	Fair	Excellent
Throwing Power:	Fair – Poor	Excellent
Impurity Resistance:	Poor	Excellent
Deposit Efficiency:	15-16%	34-35%
Deposition Rate(2 ASI):	0.0007”/hr.	0.00125”/hr.

Crack Structures
On the surface, all chrome deposits look pretty much the same, especially after they have been polished. The metallurgical structure of the deposit, however, varies drastically depending upon the type of process used.
Conventional chrome baths produce a microstructure that is quite coarse when viewed under a microscope. This limits the desired properties of the deposit. Chrome deposits produced in a Dura bath, however, show considerable improvement in important areas like hardness, wearability, grain size, and corrosion resistance.
The following photomicrographs shown the difference in deposits plated in a conventional bath and a Dura bath.

The Dura Bath Additives complies with Federal Specifications:

QQ-C-320	ASTM B-177
MIL-C-7460	AMS 2406
MIL-C-20218	AMS 2407
MIL-C-23422	AMS 2438
MIL-STD-1501	BAC 5709
DOD-STD-2182	NAVSHIPS 0919-000-9010
MIL-C-23422