What does the h and b on the pencil mean

H and B are the hardness symbols on the barrel of the pencil, H represents the hard pencil, and the larger the number in front of it, the greater the hardness; b stands for soft pencil, and the larger the number in front, the softer the refill. hb stands for pencil with moderate hardness and softness, which is suitable for everyday writing.

The higher the h-value, the harder and lighter the lead core; The higher the b-value, the softer the lead core and the darker the color.

Both Hb and F indicate moderate, with Hb being moderately slightly darker (common) and F being moderately slightly hard (rare). The higher the number in front of h, the harder the lead core and the lighter the color. The higher the number in front of b, the darker and darker the color.

The classification of pencil shafts is based on the amount of graphite in the refill. Among them, Class H pencils have relatively high refill hardness and are suitable for objects with relatively hard or clear interfaces, such as woodworking scribing, field drawing, etc.; The refill of HB pencil has moderate hardness, which is suitable for writing under general circumstances, or for contouring; Type B pencils with relatively soft refills are suitable for drawing and can also be used to fill in some machine-recognizable cards. For example, we often use a 2B pencil to fill out answer sheets.

The h and b printed on the pencil are the hardness markers of the pencil core. Generally, H is used for a hard pencil, B for a soft pencil, HB for a pencil with moderate hardness and softness, and F for a pencil with a hardness between Hb and H. The higher the number in front of h, the harder the lead core and the lighter the color.

The higher the number in front of b, the softer the lead core and the darker the color.

H class pencil, pencil refill hardness, more suitable for woodworking line drawing, drawing, etc., while writing is recommended to use Hb type, scribbling answer sheets, painting and other recommended use B pencil.

The appearance of the pencil barrel has a wrapping mold or the use of pencil paint technology, on the one hand, it can protect the pen barrel, on the other hand, it can increase the appearance, but the pigment will contain trace heavy metals, a small amount of contact will not have an effect, but biting the pen barrel to eat the mouth is still harmful.

In painting, the B-type pencil has a moderate lead quality and is suitable for sketching, and it is sometimes used for white drawing, and the H-type lead is harder and suitable for white drawing, but because of its hard lead, it is rarely used. Carbon lead and carbon strip sketches are also commonly used in paintings.

The full name of HB is: Hardness Black means pencil with hardness or gray scale in the middle (slightly blacker).

b--black

h--hardness, the more hardness b number, the darker and softer the pencil, and the more h number, the harder and lighter the color. HB is intermediate. The HB pencil is suitable for writing, while the B pencil is suitable for drawing, and the H pencil is suitable for making marks on hard objects.

The full name of CD is: Compact Disc refers to laser discography.

The full name of the BBC is: British Broadcasting Corporation refers to the British Broadcasting Corporation.

The British Broadcasting Corporation (BBC) for short.

Founded in 1922, it is the largest news broadcaster in the UK and one of the largest in the world.

Although the BBC is a public institution that receives financial support from the United Kingdom, it is managed by a 12-member regulatory committee independent of the United Kingdom, and its independence is guaranteed by a royal charter.

The Governing Council administers the BBC as a trustee in the public interest, and they are all prominent members of the community, including the Heads of Scotland, Wales, Northern Ireland and England, nominated by the Prime Minister of the United Kingdom and appointed by the Queen of England.

The B macro on the pencil scrolls to show the black degree and the h represents the hard hardness. The more the number of B, the darker and softer the pencil, the more the number of H, the harder and lighter the color, and the HB is in the middle. From soft to hard, they are 6b, 5b, wide and shout 4b, 3b, 2b, b, h, hb, 2hb, 3hb, 4hb, 5hb, and 6hb.

Pencils are mostly made of graphite, one of the allotropes of carbon. Pencils are classified according to the amount of graphite in the refill. It is generally divided into three categories: H, HB and B.

Among them, Class H pencils have relatively high refill hardness and are suitable for objects with relatively hard or rough interfaces, such as woodworking marking, field drawing, etc.

b--blackBlackness

h--hardHardness cavity hunger

1. The hardness mark of the pencil and lead core is generally used"h"Indicates a hard pencil"b"Indicates a soft pencil"hb"It means that the hardness and softness are moderateof pencils,"f"Indicates a pencil with a hardness between Hb and H

2. The larger the number in front of H, the harder the lead core and the lighter the color.

3. The larger the number in front of B, the softer the lead core and the darker the color.

4. Arrangement (From soft to hard9b, 8b, 7b, 6b, 5b, 4b, 3b, 2b, b, hb, f, h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h and other hardness and other side circle search grades.

Use caution

1. Are pencil leads toxic? In fact, pencil leads are not poisonous. Lead is poisonous, and the main raw materials for making pencil leads are graphite and clay, which of course is not poisonous.

The main components of the pencil refill are graphite and clay, graphite is a solid with a metallic luster in the form of scales, which has carbon-carbon chemical bonds, between the layers is van der Waals force, carbon-carbon chemical bonds are very stable, it is very difficult to break, which is why diamond and graphite are composed of carbon, but the physical properties are very different from **, there is nothing in the human body that can destroy the carbon-carbon chemical bonds, so it is certain that the pencil lead is safe (unless the clay added inside is harmful to human health).

2. Is the pencil barrel metal poisonous?

The appearance of the pencil barrel has a wrapping mold or the use of pencil paint technology, on the one hand, it can protect the pen barrel, on the other hand, it can increase the appearance, but the pigment will contain trace heavy metals, and a small amount of contact will not be affected, but it is not appropriate to bite the pen barrel to eat in the mouth.