SANAA
UREMBO NA USTAWI
UJANJA
UTAMADUNI NA HISTORIA
BURUDANI
MAZINGIRA
CHAKULA NA VINYWAJI
UHANDISI WA KINYUME
SAYANSI
MICHEZO
TEKNOLOJIA
VAZI
Forged Centre Punch, Hardened and Tempered
A centre punch marks the spot for a drill. It is forged from tool steel like a cold chisel: the point is tapered at a yellow heat and ground to an angle between 60° and 90°. Only the point is hardened: heat the end about 3 inches back, dip the point in water at about 70 °F (21 °C) while moving it, polish it, and let the heat left in the shank run down until the point turns brown or purple, about 500–525 °F (260–275 °C); then cool it completely. A good punch marks tool steel without its point going dull.
Kati
1–2 hours
Maagizo
1
1
Forge the taper
Forge the taper
Heat the end of the tool steel bar to a yellow heat and forge a long taper to a blunt point; finish just above the hardening heat, never hammering it black.
Vifaa kwa hatua hii:
Kipande cha pembe nane cha feleji ya zana1 kipandeZana zinazohitajika:
Fua ya mhunzi
Fuawe
Nyundo ya Kufua
Koleo la forji2
2
Cool and grind
Cool and grind
Let it cool slowly, then grind the point to an angle between 60° and 90°.
Zana zinazohitajika:
Jiwe la kunoa la gurudumu3
3
Harden the point
Harden the point
Reheat about 3 inches of the point end to the hardening heat, keeping the tip high in the fire. Dip the point into clean water at about 70 °F, moving it so no sharp line forms, then plunge briefly and lift out with heat left in the shank.
Zana zinazohitajika:
Fua ya mhunzi
NdooKoleo la forji4
4
Temper
Temper
Polish the point quickly and watch the colours run down to it; when the point is brown or purple, cool the whole punch completely.
Zana zinazohitajika:
Kitambaa cha emeriNdoo5
5
Test
Test
Strike a mark in a piece of tool steel; the point should not dull.
Zana zinazohitajika:
Nyundo ya KufuaVifaa
1- Kishikilia Nafasi
Mchoro huu unatengeneza
Blueprint zinazohusiana
Blueprint hizi zinashiriki maarifa — mbinu, vifaa au kanuni
CC0 Umma Wote
Mchoro huu umetolewa chini ya CC0. Uko huru kunakili, kubadilisha, kusambaza, na kutumia kazi hii kwa madhumuni yoyote, bila kuomba ruhusa.
Saidia Mtengenezaji kwa kununua bidhaa kupitia Mchoro wao ambapo wanapata Kamisheni ya Mtengenezaji iliyowekwa na Wachuuzi, au unda marudio mapya ya Mchoro huu na uiunganishe kama kiungo katika Mchoro wako kuchangia mapato.