Wire Rope -
The flexible wire rope is most commonly used for running rigging applications. It is strong, medium flexible cable; commonly used for wire halyards. Each of the seven strands consist of 19 individual wires, which is oil free and highly polished. "BL" is the breaking load and "WLL" is the maximum working load recommended. 316 is the suggested alloy for corrosive enviornments.
We have Sizes 0.15 - 40mm available along with some other sizes, send a request for quotation page to find out if we can offer what you need.
Braided Cable -
Stainless Steel Conductor
Stainless steel strands braided into an oval construction.
Useful for shielding and bonding purposes in commercial applications requiring special corrosion resistance.
Elastic Stretch -
Once a cable has bedded down it will obey Hookes Law; elastic stretch will be proportional to the load applied. Resistance to this stretch is determined by the modulus of elasticity.
Hookes Law -
One of the properties of elasticity is that it takes about twice as much force to stretch a spring twice as far. That linear dependant of displacement upon stretching force is called Hookes law which can be expressed as:
= -k dL
- = Force in Spring (N)
- k = Spring constant (N/m)
- dL = Elongation of the spring (m)
Break Load Example -
It should be noted that stainless steel wire rope and strand will start to distort at around 50% of its breaking load. It is therefore advisable not to load cables to more than 50% of their breaking loads.
Ultimate Tensile Strength -
The UTS of a material is the limit of stress at which the material actually breaks, with sudden release of the stored elastic energy.
Strain can be expressed as:
Strain = dL / L
- Strain - m/m or in/in
- dL = Elongation or compression (offset) of the object (m) (in)
- L = Length of the object (m) (in)
Yield Strength -
Yield Strength, or the yield point, is defined in engineering as the amount of stress the material can undergo before moving from elastic deformation into plastic deformation.
Stress can be expressed as:
Stress = F / A
- Stress = (N/) (lbs/, psi)
- F = Force (N) (lb)
- A = Area of object () ()
Here is a wire temper chart:
||1 number hard
||2 numbers hard
||4 numbers hard
||6 numbers hard
||8 numbers hard
|Extra Spring Hard
||10 numbers hard
Elastic Stretch = (W x L) / (E x A)
W = Applied Load ( kN )
L = Cable length ( mm )
E = Strand Modulus ( kN/mm2)
A = Area of Cable = (D2 x pi) / 4 (where D= Dia of cable mm)
Typical values for E are:
1x19 = 107.5 kN / mm 2
7x7 = 57.3 kN / mm 2
7x19 = 47.5 kN / mm 2
Dyform = 133.7 kN / mm2
Rockwell Hardness - (HRB or HRC)
Standard method for measuring hardness (resistance to penetration) of materials, expressed as a number assigned to the depth of penetration of a diamond cone or a steel ball. The test measures the hardness by pressing an indentor into the surface of the steel with a specific load and them measuring how far the indentor was able to penetrate.
There are several scales of Rockwell Hardess:
- A - Extremely Hard Materials
- B - Medium Hard Materials
- C - Materals reading over 100 on the B-Scale, also most common.
- Example - Hardened Tool Steel reads 62 on the C scale, and is identified as 62Rc.
Brinell Hardness Number - (BHN)
The Brinell Hardness test is commonly used to determine the hardness of materials like metals and alloys. The test is achieved by applying a known load to the surface od the tested material through a hardened steel ball of known diameter. The dimameter of the resulting permanent impression in the tested material is measured and the Brinell Number is Calculated as:
BHN = 2 F / (D (D - ))
- BHN - Brinell Hardness Number
- F = Load on indenting tool (kg)
- D = Diameter of steel ball (mm)
- d = measure diameter at rim of the impression (mm)
It is desireable that the test load are limited to a impression diameter in the range of 2.5 - 4.75 mm. (image below)
Young's Modulus - (Tensile Modulus)
Young's Modulus can be expressed as:
E = stress / strain = (F / A) / (dL / L)
- E = Young's Modulus (N/) (lbs/, psi)