This Abomb 79 podcast episode begins with hosts Adam and Abby Booth recounting a humorous yet cautionary tale of a failed outdoor recording session plagued by unexpected noise, leading into a personal safety blunder by Abby during a recent machining video. This anecdote serves as a springboard for an in-depth discussion on shop safety, emphasizing the critical importance of eye and hearing protection.
The core of the episode delves into the nuances of threading terminology, referencing "The Dictionary of Metalworking Terms." Adam clarifies definitions for "chasing," "chasers" (used in geometric die heads), "dies" (for external threads or metal forming), "die stock," and "taps" (for internal threads, including taper, plug, and bottoming types). He addresses the "controversy" between straight and angular infeed methods for single-point lathe threading, advocating for angular infeed's efficiency. The hosts also compare the quality of threads produced by single-point threading versus dies, highlighting the professional finish of the former. The episode concludes with a listener's "Abomb Inspiration Story" from a third-generation machinist who expanded his business using knowledge gained from Adam's channel, and a brief discussion of Adam's tap wrench collection.
Abomb 79 Podcast: Shop Safety, Threading Terminology, and Inspiring Stories
0:06 Podcast Introduction & Outdoor Recording Woes: Hosts Adam and Abby Booth introduce the podcast, recounting a failed outdoor recording attempt during the Labor Day holiday due to unexpected noise (airplanes, fire engine, lawnmower), highlighting a running joke about noise appearing whenever they try to film outside.
0:59 Abby's Safety Blunder: Abby confesses her "worst blunder" while filming Adam threading 304 stainless steel rods: forgetting safety glasses and wearing open-toed sandals, resulting in hot chips hitting her feet. She engaged in "safety squints."
1:36 Emphasis on Shop Safety: Abby, having recently read a machinist safety book, now understands the importance of safety even more. Both hosts stress the necessity of safety glasses for eye protection and caution against casual footwear in the shop.
2:28 Importance of Hearing Protection: Adam shares his experience with ear ringing, which he attributes to a lack of hearing protection from loud noises (grinders, hammers, power tools) earlier in his career. He advises young machinists to protect their hearing early.
3:17 Introduction to Threading Terminology: Adam transitions to discussing the previous video's threading job, specifically his use of the term "thread chasing," which he knew might be controversial. He introduces "The Dictionary of Metalworking Terms" as a reference.
4:10 "Chase" & "Chasers" Defined: Adam explains that a geometric die head uses components called "chasers," and operating this tool can be considered "thread chasing," even when cutting new threads, challenging the common perception that "chasing" only applies to cleaning existing threads.
5:28 "Die" & "Die Stock" Definitions: The dictionary defines "die" as both a round threading tool for external threads and a metal-forming tool. The "die stock" is the handle used to turn a round die.
6:49 "Tap" & Its Types: Discussion moves to internal threads, cut by "taps." Adam explains the three types: Taper (for starting), Plug (for general use), and Bottoming (for threading to the bottom of a hole). He clarifies that "chasing" is for external threads and "tapping" for internal threads.
8:50 Lathe Threading Methods Controversy: Adam addresses the debate between straight infeed and angular infeed for single-point threading on a lathe. He prefers angular infeed (compound slide at 29.5 degrees) for its efficiency and consistent zero-point reference, while acknowledging that both methods can achieve good results.
10:56 Single-Point Threading vs. Dies for Quality: Adam explains that single-point threading on a lathe produces superior, cleaner, and more professional threads compared to using a die, allowing for spring passes and thread reliefs. The choice of method depends on the job's precision and aesthetic requirements.
12:28 Adam's Tap Wrench Collection: Abby asks about Adam's smallest and largest tap wrenches. His smallest is a Starrett (approx. 3 inches), and his largest is a Greenfield Tap and Die number 24 (about 72 inches with handles), designed for two people. He values old, color-case hardened tap wrenches as representations of manual machining.
16:32 Listener "Abomb Inspiration Story": Marty from Blockhead Machine, a third-generation machinist, shares how Adam's YouTube channel helped him learn to operate a knee-mill, expanding his custom automotive engine business into one-off parts for the boat racing industry. Marty credits Adam's content for teaching him in a relatable way.
17:55 Call to Action: The hosts encourage listeners to send their shop stories and photos, provide feedback, ask questions ("Ask Abbomb"), and check out their social media (YouTube: Abom79, ABOM Adventures; Instagram, Facebook) and merch store (a79.com).