The Combat Knife is the standard wargear for all Space Marines, made of Ceramics with a monomolecular edge. 

The Frag Grenade is the standard grenade in the 40k universe.
If it explodes it catapults dozens of razorsharp shrapnels which cut through armour and flesh. 
  
The Bolt Pistol is the little brother of the Bolter.
It has a decreased range, less rate of fire but the same penetration power. 

The Bolter-Flamer is an early combi-weapon, combining a Bolter and a Flamer.
Its both for short and long range fights pretty usable.
The invention of combi-weapons eventually led to the creation of the Storm Bolter.
