Technical Info

Loading Assumptions

Wherever possible throughout this product range, the Breaking Load is stated as supplied by the manufacturer, normally in Kg (kilograms). Where other units are used these are indicated on the appropriate pages.

Breaking Loads are for guidance only and do not form part of any warranty. All loads are quoted assuming a straight pull using shackles to secure to the test equipment. Where the load on a buckle is not straight the strength could be reduced.

Where formulas have been used to obtain a components breaking load, etc. an ultimate tensile stress has been assumed of:

500N/mm2 for Stainless Steel
300N/mm2 for Aluminium
350N/mm2 for Carbon Steel

In many tests we have made where buckles, D rings, etc. have been pulled using webbing, failure of the webbing occurs before the product reaches its Breaking Load. Our test data is available on request and tests can be made on customers applications if required.

Buckles are used in a variety of applications and factor of safety for Safe Working Loads (SWL) may vary. Our recommendation is that the Safe Working Load be one fifth of the Breaking Load.

It is the obligation of the purchaser or user to determine whether or not each item is suitable for its intended use. In no event shall our liability extend beyond the replacement cost of any item.

Lifejacket Buoyancey

50N Buoyancy Aids
- Provide 11lbs/5.5kg buoyancy and conform to standard EN393
- Only suitable for competent swimmers
- Sheltered water use where help is close at hand
- Only provides support to conscious people who can help themselves

150N Lifejackets
- Provide 33lbs/16kg buoyancy and conform to Standard EN396
- Suitable for swimmers and non-swimmers
- For use in all but the most severe conditions
- They will give reasonable assurance of safety from drowning to people not fully capable of helping themselves
- May not immediately self-right and unconscious user wearing heavy waterproof clothing


To convert newtons to kilograms multiply by 0.102.

Use our weights converter to change many different weight units.

Use our length converter to change many different length units.

For a printed conversion chart click here.

Stainless Steel

Stainless Steel is the name given to a large group of Steel Alloys with many differences in properties and behaviour, all of which contain more then 10.5% Chromium, so have a resistance to corrosion. This is due to the fact that Chromium has a high affinity for oxygen and forms a tenacious, stable Oxide film that is resistant to further chemical or physical change.

The Austenitic group of Steel Alloys contains Chromium in the range of 17-25% and Nickel in a range pf 8-20% with various additional elements to achieve different properties. The following three types are most commonly used in the marine trade:

Type 302 A basic 18% chrome 8% Nickel grade from which the majority of other forms have been developed. Its properties make it the most suitable for the manufacture of stainless steel springs.

304 Stainless Steel

Type 304(A2) Similar to 302 but due to lower Carbon content, is less susceptible to inter-granular corrosion after welding. With reasonable resistance to corrosion, it is suitable for applications where there is limited exposure such as fittings below decks.

Type 316 (A4) This is a Molybdenum bearing Stainless Steel designed for applications involving severe corrosion conditions and is non-magnetic. It is therefore most suitable for marine use, especially for sail hardware and on deck applications where there is high exposure to salt water.

Stainless Steel Information PDF's to download from the North American Stainless Steel Informaiton Centre

The Care and Cleaning of Stainless SteelThe Care and Cleaning of Stainless Steel Stainless Steel for Coastal and Salt Corrosion ApplicationsStainless Steel for Coastal and Salt Corrosion Applications
Stainless Steel for Structural ApplicationsStainless Steel for Structural Applications Stainless Steel FabricationStainless Steel Fabrication
Stainless Steel FastenersStainless Steel Fasteners Specifications for Stainless SteelSpecifications for Stainless Steel
Welding of Stainless Steels and Other Joining MethodsWelding of Stainless Steels and Other Joining Methods Stainless Steel Architectural FactsStainless Steel Architectural Facts
Get Adobe Reader here

TIG Welding

All Makefast products using welded construction are welded using the Tungsten Inert Gas (TIG) System. This is vital for consistent high quality welds in Stainless Steel and is recognized as the industry standard procedure for all high load welded structures.

TIG welding Although more costly than standard arc welding, Makefast insist on all its welded products using this method. Baseline believe that for safety equipment no shortcuts can be made in quality. Therefore when you see the logo for TIG welding, be assured the product is of the highest quality.

Whats wrong with standard arc welding?
When welding takes place the material being joined is heated to very high temperatures, using an electric arc between the electrode and welding jig, until it liquefies in localized areas in the weld region. The weld comprises of the fused material with a portion of welding consumable which when cooled forms a solid mass of material.

With standard non-shielded welding, the high temperatures cause oxidation to be introduced into the weld area so causing impurities and weakness in the final weld.

With TIG welding, a tungsten electrode is used to create a high temperature electric spark which melts the surrounding material. The weld area is shielded by an inert gas (usually argon) which prevents oxidization in the weld area. Furthermore, the welding process uses a stainless steel filler rod of the same constituent material as the component so ensuring material strength is not reduced.

Plastic Mouldings

The Makefast plastic products, when used for loaded applications are manufactured using Nylon 6, Nylon 66 or Acetal. Non loaded products are generally manufactured in polypropylene.

The colour of plastic products does affect the price due to the high cost of certain pigments used to colour the base plastic material. As a general rule, reds and yellows will be more costly than blues and dark colours.

Makefast use a range of sophisticated microprocessor controlled injection moulding machines capable of moulding a range of engineering thermoplastics. The advantages of these machines include full and detailed control over the moulding cycle, ensuring the highest quality results in a range of materials. The advanced mixing systems ensure consistency in colour matching throughout a production run and additives can be strictly controlled to achieve the desired effect, be it for colour, fire resistance or increased strength.

Makefast reduce waste by recycling plastic and manufacture several non-load bearing products using this reground material.

Lanex Rope Material Properties

Lanex ropes and cords reach excellent parameters and are resistant to the most severe weather conditions, UV radiation as well as abrasion of the highest degree. Instead of natural materials, we use synthetic fibres which, if compared with natural fibres have better properties such as greater strength, lower elongation and longer service life.

The following table shows the properties displayed by the individual materials:

High tenacity poly-
Aramid fibres
Polypropylene multifilament
Trade name
Dyneema, Spectra
Technora, Kevlar, Twaron
Dacron, Diolen, Trevira
Nylon, Perlon, Enkalon
at break (%)
Specific gravity
Melting point
carbonization at 500C
Abrasion resistance
UV resistance
Salt resistance
predominantly good
good at room temperature
good at weak concentration
good at weak concentration
Resistance to acids
predominantly good
predominantly good
predominantly good
Resistance to oil products
creeps under high tension
hardly measurable
hardly measurable
creeps slightly under tension
creeps under high tension
Knot strength

**Specific tenacity related to fibre fineness
The data given in the table is for reference only.

It is suitable to use materials having low elongation, high strength and long service life for sheet and halyard ropes. From a wide assortment of materials polyester is used in most cases, but new high-tenacity materials like Dyneema and Vectran are gaining importance for demanding racing applications.
Mooring, anchor and tow ropes have to be able to absorb heavy shocks and repeatedly occurring tension, thus they have to be elastic and strong. While floating materials such as polypropylene are suitable for use as lightweight tow ropes, heavier materials such as polyamide and polyester are ideal as mooring and anchor ropes.

The American Iron and Steel Institute Standardized Numbered AISI Steel Grades*

A2 Stainless Steel and A4 Stainless Steel are 'Fastening Grades'. A2 is similar in properties to 304, and A4 is similar in proprties to 316.


  • Type 304the most common; the classic 18/8 stainless steel.
  • Type 316the next most common; for food and surgical stainless steel uses; Alloy addition of molybdenum prevents specific forms of corrosion. Also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.


DIN - German Institute for Standardization

DIN Deutsches Institut fr Normung e.V. ( DIN ; in English , the German Institute for Standardization ) is the German national organization for standardization and is that country's ISO member body.

There are currently around thirty thousand DIN Standards, covering almost all fields of technology. One of the earliest, and surely the most well-known, is DIN 476 , the standard that introduced the A4, etc. paper sizes in 1922 . This was later adopted as international standard ISO 216 in 1975 .

DIN is a registered association ( e.V. ), founded in 1917 , originally as Normenausschuss der deutschen Industrie (NADI, Standardisation Committee of German Industry). In 1926 the NADI was renamed Deutscher Normenausschuss (DNA, German Standardisation Committee) in order to indicate that standardization now covered many fields, not just industrial products. In 1975 the DNA was finally renamed DIN. Its headquarters is in Berlin . Since 1975 it has been recognized by the German government as the national standards body and represents German interests at international and European level.

DIN hompage