Best Parabolic Spring

IRWIN SPEEDBOR Spade Wood Drill Bit 7/8'X 4' (87914) , Black

The Zhumell Z8 Dobsonian telescope features an 8” parabolic primary mirror that captures a substantial amount of light..
Produces crisp, bright images free of visual defects like spherical aberration..
A durable, sturdy construction means your Zhumell will stand up to years of use at public star parties, camping trips, and more..

The Zhumell Z12 Dobsonian telescope features a massive 12” parabolic primary mirror that captures a substantial amount of light..
Produces crisp, bright images free of visual defects like spherical aberration..

2" long X .6" high and only weigh's 6 grains.
Designed to be used with both fixed and mechanical broadheads, and yet also outperforms with field points for target shooting.

Designed to cut wrought iron, cast iron, steel, brass, bronze, copper, aluminum, bolts, nuts and rivets.
Modified parabolic striking end to help reduce mushrooming and chipping.

16mm patented square parabolic shackle (19mm coating).
The shackle, lock body and supporting elements of the locking mechanism are all made of special temper hardened steel.
ABUS X-Plus Cylinder offers extremely high protection against picking.
Two keys supplied with the lock, one LED lighted.

Quality optical design--parabolic mirror provides sharp image and eliminates spherical aberration.
Fast focal ratio offers a wide field of view, perfect for observing comets, star clusters, galaxies, and more.
No-tool setup means you are up and observing in no time.
Lightweight and portable, a great grab-and-go telescope.
Large aperture collects more light and provides more detail.

...Operations). Working materials include steel, copper, aluminum, zinc alloy, cast iron, wood and plastics..
【HSS Titanium Coating】High speed steel (HSS) with titanium coating gives Jefe Hex drill bits great durability and prolongs 3 times longer life than drill bits without coating..
【135 Degrees Split Point and Parabolic Flute】Jefe Hex Easy Cut Split Point design makes drilling easy with less pressure and prevents drill bits walking on the working surface. Fully ground modified parabolic flute design clears chips quickly, decreases friction and heat damage. Tapered web provides durability and reduces breakage..
【Quick Change Solid Hex Shank】1/4" (6.35mm) hex shank fits into standard power tools and impact drivers. Jefe Hex drill bit’s solid bonding technology eliminates radial runout and improves concentricity. High torque, impact-rated accuracy..