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Bob's Knobs Collimation Knobs For Celestron SCT 5" F/10 - Metric

Bob's Knobs Collimation Knobs for Celestron SCT 5" f/10 - Metric

Bob's Knobs
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Estimated Arrival: Between Dec 06 and Dec 12. *ETA to USA Only

Shipping & Returns: Satisfaction guaranteed 30 day return policy.


Bob's Knobs offers knobs for the Celestron 5” Schmidt-Cassegrain secondary with either standard or metric collimation screws in the f/10 and rare f/6 versions. Please use care to select the correct knobs for your telescope. Each knob set is different and they are not interchangeable. Price is for a complete set of knobs.

Fits: Celestron 5” (13 cm) f/10 SCT (C5, NexStar 5SE, Omni 127) with black Phillips factory collimation screws. These screws have metric threads. Will NOT fit scopes with silver factory collimation screws


  1. These knobs will fit only 2006 and later C5 models that have black Phillips factory collimation screws. All C5 models made prior to 2006 and all post-2006 models with black Allen or silver factory collimation screws require C5 standard knobs (Item A above). Check that our screw threads match the factory screw threads before installing.
  2. Some C5 scopes have metric collimation screws that are 10mm long rather than the more common 8mm. If your secondary looks like this, you have screws with 10mm thread length and you should install knobs without the white spacers.
  3. Black oxide steel (shown in photo) is for dry environments. Lightly oil the knob top and knob serrations periodically as an anti-corrosion measure. Stainless steel provides better corrosion protection in coastal or high humidity areas, or in places where dew or other condensation is common.
  4. The factory dust cover will fit normally with Bob's Knobs installed.
  5. Some telescope versions have a small plastic cover over the factory collimation screws. This cover must be removed and set aside when Bob's Knobs are installed. The cover is cosmetic only and will not affect operation of the scope.
  6. The Celestron 5” SCT uses either standard 6-32 or metric M3 collimation screws. Allen and silver Phillips factory collimation screws have standard threads. Most black Phillips screws are metric. If you order knobs with the wrong screws, contact us for return instructions.



Black oxide steel (black) or stainless steel (silver), 12mm (1/2") diameter


Black oxide or stainless steel


We know that once you've placed your order, you are anxious to receive it! We make every effort to get your order shipped out to you as quickly as possible.

As soon as you place your order, you will receive an order confirmation e-mail. This means that we have received your order in our system and pre-authorized your credit card for the purchase. We will process the charges to your credit card and your order will ship within five business days from the date of your order. We will send you tracking information within 24 hours of your order leaving the warehouse to the e-mail address you provided when checking out.  If you do not receive tracking information from us within six business days of your order, feel free to follow up with us at

Standard shipping time in the US is between 3-5 business days, though it can vary slightly depending on the destination. We typically For updates on your shipment you can enter your tracking number here.

We distribute nationwide via UPS and Fedex. Unfortunately, at this time we are not able to provide expedited or international shipping.