Page 316 - Content.pmd

• vÀh úYLm ªL A§LUôL CÚjRp (feed
rate is too high)
• CûPùY°d úLôQm N¬«uûU
(clearance angle is incorrect)
• Ï°o®l×j§\u Ïû\Ü (cooling is ineffective)

• Øû]dúLôQm N¬«uûU (point angle is
incorrect)
• ¥¬p áoûUVôL CuûU (drill is not sharp) EûPkR ¥¬p ApXÕ CûPlTôLm

LWÓØWPô] Õû[Ls (Rough holes) ©[ÜßRp (Split web)
Õû[Ls LWÓØWPôL CÚlT§u CRtÏ ¸rLiP LôWQeLs EiÓ
LôWQeLs • ùYhÓ úYLm ªL A§Lm

• @Àh úYLm ªL A§Lm • @Àh úYLm ªL A§Lm
• ¥¬pL°u ùYhÓ ®°m×Ls áoûUVtß • T¦lùTôÚs EߧVôLl
CÚjRp §\Ut\ Ï°o®lTôu Øû\. ©¥dLlTPôUp CÚjRp
©£oLs NUªu± ùY°úVßRp (Unequal • RUo N¬VôL ©¥dLlTPôRÕ
flow of chips) (Fig 5 )
• RU¬u áoûU«uûU Øû]d úLôQj§u
NUªu± ©£oLs ùY°úVßYRtLô] A[Ü N¬«uûU
LôWQeLs ùYhÓ ®°m×Ls NUUôL
• Ï°ìhÓRp Ïû\Ü
CpXôRÕ
• ×ÞhL°p (flutes) ©£oLs £d¡«ÚjRp
Øû]«u úLôQm ¥¬pXõu ûUVj§p
AûUVôUXõÚjRp

¥¬pL°p GÝjÕ Utßm Gi (Letter and number drills)

úSôdLeLs: ClTôPj§u Ø¥®p ¿eLs ùT\ úYi¥V A±Ü §\uLs
• ¥¬p A[®u GÝjÕ Utßm Gi ùRôPoLû[d á\p (Range of drill sizes)
• AhPYûQûVl TôojÕ GÝjÕ Uôtßm Gi YûL ¥¬pL°u ®hP A[ÜLû[d
á\p.

ùTôÕYôL ¥¬pLs ¨oQ«dLlThP RWUô] A þu A[Ü 5.944ªÁ ®hP A[Ü
ùUh¬d A[ÜL°p ¡ûPd¡u\]. CkR BÏm. Z þu ®hP A[Ü 10.490ªÁ. CÕRôu
¥¬pL°u A[ÜLs ϱl©hPlT¥ Øû\ A[®p A§LUô]Õ (AhPYûQ 1 þp
A[®p CÚdÏm. CkR A[Ü Øû\L°p LôhPlThÓs[Õ.
APeLôR A[ÜLs, GÝjÕ Utßm Gi
GÝjÕ Utßm Gi YûL RUoL°u N¬Vô]
YûL ¥¬pL[ôLd ¡ûPd¡u\].
®hP A[ÜLû[ NmTkRlThP ¥¬p
CkR YûL ¥¬pLû[ Y¬ûN Øû\Vt\ A[®«u ER®Vôp N¬TôodLXôm. CkR
A[Ü Es[ Õû[Lû[«Pl ¥¬p A[® ùNqYL ApXÕ NÕW
TVuTÓjRXôm. Y¥Yj§Xô] EúXôLlThûPVôÏm. C§p
GÝjÕ YûL RUoLs (Letter drill) TpúYß ®hP A[ÜLÞdÏ Õû[L°Pl
Th¥ÚdÏm. AkRkR Õû[«u AÚúL ARu
GÝjÕ YûL RUoLs ‘A’ ØRp ‘Z’ YûW«Xô] N¬Vô] A[Ü ùTô±dLlTh¥ÚdÏm.
GÝjÕdL[ôp AûUk§ÚdÏm. ªLf£±V

£_õ & Gm: @©hPo (NSQF - Revised 2022) ------ R.T. for Ex. No.1.5.72-73 295