A school banned pencil sharpeners after a 10-year-old boy took one apart and used the blade to injure a classmate.
The victim required stitches after the incident
The head of Waterloo Primary School, in Ashton-under-Lyne, Gtr Manchester, took the decision after the boy was slashed in the neck and needed stitches.
Greater Manchester Police later questioned his attacker, who was suspended for a number of days.
Tracy Buckley, the school's head of governors, said a fixed period of exclusion was "entirely appropriate".
A spokeswoman for Tameside Council said it had been kept "fully informed" about the incident, which happened in November.
"The council fully supported the actions taken by the school and governors who responded appropriately, and all procedures were followed," she said.
"The school took the incident very seriously and the governors, head teacher and staff are committed to providing a safe and secure environment for all pupils."
The injured boy required stitches to his wound, but has now returned to school. The council said his parents had decided not to lodge a formal complaint about the incident.