Human hair growth a new strand of hair begins to form. The rate or speed of hair growth is about 1.25 centimetres or 0.5 inches per month, or about 15 centimetres or 6 inches per year. The anagen phase is known as the growth phase. This is the phase where the hair physically grows approximately 1 cm per month. It begins in the papilla and can last from two to six years. The span at which the hair remains in this stage of growth is determined by genetics. The longer the hair stays in the anagen phase, the longer it will grow. During
15 cm/45 41st Year Type Japanese designation system for artillery changed from inches "6 in/45 41st Year Type" to centimeters "15 cm/45 41st Year Type". Whether the guns originated in Britain or were built in Japan they still shared the same 41st Year designation. The 15 cm/45 41st Year was constructed of an A tube and wire wound with a protective outer jacket. Ships built in British shipyards for Japan were armed with Pattern GG guns and later Japan produced their own versions under license at the Kure Naval Arsenal. Four different models were produced at Kure which differed in the style of rifling used.