A single strand can potentially carry a weight of up to 100 grams (3.5 oz); in theory, with proper technique, a full head of human hair could eventually hold between 5,600 kg and 8,400 kg (12,345 to 18,518 lbs) without breaking individual hairs or pulling out any follicles.
A single scalp hair can hold a weight of 100g and an average head of hair twist together can support 23 tons. Hair grows from a single follicle – an indentation in the skin.
Just one strand of our hair can withstand a massive amount of stress and if you combine all of the hairs found on our heads (approx 150,000), the amount of weight they can support can equal the same weight as 8 small cars!
A single strand could hold 100g (3oz) in weight: the combined hair of a whole head could support 12 tonnes, or the weight of two elephants. Weight for weight, it is not as strong as steel: more like aluminium, or reinforced glass fibres or Kevlar, which is used to make bulletproof vests.
Based on studies from East Africa, it is suggested that up to 20% of the person's body weight can be carried on the head with no extra exertion of energy. This means that for instance a person of 60 kg can carry 12 kg, or a man of 80 kg can carry 16 kg.
Comparison to Body Weight: Despite the sensation of weight in your hair, its actual weight is incredibly light when compared to the overall weight of your entire body. The average human head of hair, which can weigh anywhere from 100 to 150 grams, represents only a fraction of the total body weight.
To fracture the skull there would require 500 kgf, or the force that 500 kilograms (1,100 pounds) would exert in standard gravity.
Hair has a strength to weight ratio comparable to steel. It can be stretched up to one and a half times its original length before breaking. “We wanted to understand the mechanism behind this extraordinary property,” said Yang (Daniel) Yu, a nanoengineering Ph. D.
In "Beginnings", the reason behind the regrowth of Rapunzel's hair in "Before Ever After" was revealed. When she came into contact with the rocks, part of the Moonstone's powers went into her hair, causing it to grow back and become indestructible like them so she can be protected on her journey.
Mechanical properties vary among different ethnicities. Asian hair demonstrates the highest hardness and elastic modulus, followed by Caucasian and African hairs, respectively.
In most people, scalp hair growth will halt due to follicle devitalization after reaching a length of generally two or three feet (610mm - 914mm). Exceptions to this rule can be observed in individuals with hair development abnormalities, which may cause an unusual length of hair growth.
Most people learn the act from a family member. Hair hanging is a form of high-wire act. Backstage, the performer's hair is carefully braided around a steel loop. During the act, the loop is attached to a steel cable, by which the performer is lifted 15 to 35 feet (5 to 11 meters) into the air.
The keratinous fibres stretch easily, and can be extended by up to 40 percent before breaking. Previous research has found that human hair has a tensile strength of around 200–260 MPa, which is comparable to steel. You could carry a person with 500–1000 human hairs.
A rope of human liair, several inches in diameter and wveral thousand feet in length, was made for the Mikado of Japan, but having been discarded in favor of a rope of steel, this massive lock of hair, or collection of locks, has passed into the hands of the authorities of the British museum.
Elephants are Schedule-1 animals protected under the Wildlife Protection Act, 1972, under which it is illegal to sell or trade any parts, including hair, said Paranjape.
Previous studies have found that human hair has strength comparable to that of steel when adjusted for density. This is because of hair's hierarchical structure: human hair is composed of an outer layer called the cuticle that wraps around an inner cortex made of many small fibers linked by chemical bonds.
It has been suggested that a Boeing 747 could be stopped in flight by a single pencil-width strand and spider silk is almost as strong as Kevlar, the toughest man-made polymer. It is finer than the human hair (most threads are a few microns in diameter) and is able to keep its strength below -40°C.
Graphene
The tensile strength and elastic modulus of graphene are 125Gpa and 1.1tpa, respectively, and its strength is 100 times that of ordinary steel. Bags made of graphene, which can hold about 2 tons of weight, are by far the strongest material known.
The position of the head also plays a role, because the skull is not equally strong throughout: The frontal bone is the strongest part of the skull, while the weakest bones are found in the temporal region. The skull can break from a pressure of 2–6 kp (20–60 N) per square millimetre – if it is on a fixed subsurface.
There are 22 bones in the human head. The head rests on the neck, and the seven cervical vertebrae support it. The human head typically weighs between 2.3 and 5 kilograms (5.1 and 11.0 lb) Over 98% of humans fit into this range.
The pterion is known as the weakest part of the skull. The anterior division of the middle meningeal artery runs underneath the pterion. Consequently, a traumatic blow to the pterion may rupture the middle meningeal artery causing an epidural haematoma.